diff --git a/applications/utilities/preProcessing/setFields/setFields.C b/applications/utilities/preProcessing/setFields/setFields.C
index cdca73df55..14f3a5acf7 100644
--- a/applications/utilities/preProcessing/setFields/setFields.C
+++ b/applications/utilities/preProcessing/setFields/setFields.C
@@ -440,7 +440,7 @@ int main(int argc, char *argv[])
         autoPtr<topoSetSource> source =
             topoSetSource::New(region.keyword(), mesh, region.dict());
 
-        if (source().setType() == topoSetSource::CELLSETSOURCE)
+        if (source().setType() == topoSetSource::CELLSET_SOURCE)
         {
             cellSet selectedCellSet
             (
@@ -461,7 +461,7 @@ int main(int argc, char *argv[])
                 setCellField::iNew(mesh, selectedCellSet.sortedToc())
             );
         }
-        else if (source().setType() == topoSetSource::FACESETSOURCE)
+        else if (source().setType() == topoSetSource::FACESET_SOURCE)
         {
             faceSet selectedFaceSet
             (
diff --git a/src/faOptions/corrections/limitVelocity/limitVelocity.C b/src/faOptions/corrections/limitVelocity/limitVelocity.C
index fa2f484fab..a7440549a6 100644
--- a/src/faOptions/corrections/limitVelocity/limitVelocity.C
+++ b/src/faOptions/corrections/limitVelocity/limitVelocity.C
@@ -95,15 +95,11 @@ void Foam::fa::limitVelocity::correct(areaVectorField& U)
         }
     }
 
-    // handle boundaries in the case of 'all'
-    if (selectionMode_ == smAll)
+    // Handle boundaries in the case of 'all'
+    if (!cellSetOption::useSubMesh())
     {
-        areaVectorField::Boundary& Ubf = U.boundaryFieldRef();
-
-        forAll(Ubf, patchi)
+        for (faPatchVectorField& Up : U.boundaryFieldRef())
         {
-            faPatchVectorField& Up = Ubf[patchi];
-
             if (!Up.fixesValue())
             {
                 forAll(Up, facei)
diff --git a/src/faOptions/faceSetOption/faceSetOption.C b/src/faOptions/faceSetOption/faceSetOption.C
index 90d10014e7..e2436cd854 100644
--- a/src/faOptions/faceSetOption/faceSetOption.C
+++ b/src/faOptions/faceSetOption/faceSetOption.C
@@ -105,7 +105,7 @@ void Foam::fa::faceSetOption::setArea()
 }
 
 
-void Foam::fa::faceSetOption::setFaceSet()
+void Foam::fa::faceSetOption::setFaceSelection()
 {
     switch (selectionMode_)
     {
@@ -182,18 +182,18 @@ Foam::fa::faceSetOption::faceSetOption
 )
 :
     fa::option(name, modelType, dict, patch),
-    timeStart_(-1.0),
-    duration_(0.0),
+    timeStart_(-1),
+    duration_(0),
     selectionMode_(selectionModeTypeNames_.get("selectionMode", coeffs_)),
     faceSetName_("none"),
-    A_(0.0)
+    A_(0)
 {
     if (isActive())
     {
         Info<< incrIndent;
         read(dict);
         setSelection(coeffs_);
-        setFaceSet();
+        setFaceSelection();
         setArea();
         Info<< decrIndent;
     }
diff --git a/src/faOptions/faceSetOption/faceSetOption.H b/src/faOptions/faceSetOption/faceSetOption.H
index 559cacdae2..46abaed1ca 100644
--- a/src/faOptions/faceSetOption/faceSetOption.H
+++ b/src/faOptions/faceSetOption/faceSetOption.H
@@ -132,7 +132,7 @@ protected:
         //- Face selection mode
         selectionModeType selectionMode_;
 
-        //- Name of zone for "faceZone" selectionMode
+        //- Name of "volFaceZone" selection
         word faceSetName_;
 
         //- Set of faces to apply source to
@@ -144,11 +144,11 @@ protected:
 
     // Protected Functions
 
-        //- Set the face selection
+        //- Set face selection name from dictionary input
         void setSelection(const dictionary& dict);
 
-        //- Set the face set based on the user input selection mode
-        void setFaceSet();
+        //- Set face selection based on user input selection mode
+        void setFaceSelection();
 
         //- Recalculate the area
         void setArea();
@@ -181,35 +181,38 @@ public:
         // Access
 
             //- Return const access to the time start
-            inline scalar timeStart() const;
+            inline scalar timeStart() const noexcept;
 
             //- Return const access to the duration
-            inline scalar duration() const;
+            inline scalar duration() const noexcept;
 
             //- Return true if within time limits
-            inline bool inTimeLimits(const scalar time) const;
+            inline bool inTimeLimits(const scalar timeValue) const;
 
             //- Return const access to the face selection mode
-            inline const selectionModeType& selectionMode() const;
+            inline selectionModeType selectionMode() const noexcept;
+
+            //- True if sub-selection should be used
+            inline bool useSubMesh() const noexcept;
 
             //- Return const access to the name of face set for "faceZone"
             //- selectionMode
-            inline const word& faceSetName() const;
+            inline const word& faceSetName() const noexcept;
 
             //- Return const access to the total face area
-            inline scalar A() const;
+            inline scalar A() const noexcept;
 
-            //- Return const access to the face set
-            inline const labelList& faces() const;
+            //- Return const access to the face selection
+            inline const labelList& faces() const noexcept;
 
 
         // Edit
 
-            //- Return access to the time start
-            inline scalar& timeStart();
+            //- Adjust the time start, return the old value
+            inline scalar timeStart(scalar val) noexcept;
 
-            //- Return access to the duration
-            inline scalar& duration();
+            //- Adjust the duration, return the old value
+            inline scalar duration(scalar val) noexcept;
 
 
         // Checks
diff --git a/src/faOptions/faceSetOption/faceSetOptionI.H b/src/faOptions/faceSetOption/faceSetOptionI.H
index d63ee88560..1bc9b5ed25 100644
--- a/src/faOptions/faceSetOption/faceSetOptionI.H
+++ b/src/faOptions/faceSetOption/faceSetOptionI.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,19 +27,19 @@ License
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-inline Foam::scalar Foam::fa::faceSetOption::timeStart() const
+inline Foam::scalar Foam::fa::faceSetOption::timeStart() const noexcept
 {
     return timeStart_;
 }
 
 
-inline Foam::scalar Foam::fa::faceSetOption::duration() const
+inline Foam::scalar Foam::fa::faceSetOption::duration() const noexcept
 {
     return duration_;
 }
 
 
-inline bool Foam::fa::faceSetOption::inTimeLimits(const scalar time) const
+inline bool Foam::fa::faceSetOption::inTimeLimits(const scalar timeValue) const
 {
     return
     (
@@ -53,40 +53,50 @@ inline bool Foam::fa::faceSetOption::inTimeLimits(const scalar time) const
 }
 
 
-inline const Foam::fa::faceSetOption::selectionModeType&
-Foam::fa::faceSetOption::selectionMode() const
+inline Foam::fa::faceSetOption::selectionModeType
+Foam::fa::faceSetOption::selectionMode() const noexcept
 {
     return selectionMode_;
 }
 
 
-inline const Foam::word& Foam::fa::faceSetOption::faceSetName() const
+inline bool Foam::fa::faceSetOption::useSubMesh() const noexcept
+{
+    return selectionMode_ != selectionModeType::smAll;
+}
+
+
+inline const Foam::word& Foam::fa::faceSetOption::faceSetName() const noexcept
 {
     return faceSetName_;
 }
 
 
-inline Foam::scalar Foam::fa::faceSetOption::A() const
+inline Foam::scalar Foam::fa::faceSetOption::A() const noexcept
 {
     return A_;
 }
 
 
-inline const Foam::labelList& Foam::fa::faceSetOption::faces() const
+inline const Foam::labelList& Foam::fa::faceSetOption::faces() const noexcept
 {
     return faces_;
 }
 
 
-inline Foam::scalar& Foam::fa::faceSetOption::timeStart()
+inline Foam::scalar Foam::fa::faceSetOption::timeStart(scalar val) noexcept
 {
-    return timeStart_;
+    scalar old(timeStart_);
+    timeStart_ = val;
+    return old;
 }
 
 
-inline Foam::scalar& Foam::fa::faceSetOption::duration()
+inline Foam::scalar Foam::fa::faceSetOption::duration(scalar val) noexcept
 {
-    return duration_;
+    scalar old(duration_);
+    duration_ = val;
+    return old;
 }
 
 
diff --git a/src/fvOptions/cellSetOption/cellSetOption.C b/src/fvOptions/cellSetOption/cellSetOption.C
index b74fb597db..bede9ebc04 100644
--- a/src/fvOptions/cellSetOption/cellSetOption.C
+++ b/src/fvOptions/cellSetOption/cellSetOption.C
@@ -118,7 +118,7 @@ void Foam::fv::cellSetOption::setVol()
 }
 
 
-void Foam::fv::cellSetOption::setCellSet()
+void Foam::fv::cellSetOption::setCellSelection()
 {
     switch (selectionMode_)
     {
@@ -205,16 +205,16 @@ Foam::fv::cellSetOption::cellSetOption
 )
 :
     fv::option(name, modelType, dict, mesh),
-    timeStart_(-1.0),
-    duration_(0.0),
+    timeStart_(-1),
+    duration_(0),
     selectionMode_(selectionModeTypeNames_.get("selectionMode", coeffs_)),
     cellSetName_("none"),
-    V_(0.0)
+    V_(0)
 {
     Info<< incrIndent;
     read(dict);
     setSelection(coeffs_);
-    setCellSet();
+    setCellSelection();
     setVol();
     Info<< decrIndent;
 }
@@ -231,14 +231,14 @@ bool Foam::fv::cellSetOption::isActive()
         {
             if (mesh_.topoChanging())
             {
-                setCellSet();
+                setCellSelection();
                 // Force printing of new set volume
                 V_ = -GREAT;
             }
             else if (selectionMode_ == smPoints)
             {
                 // This is the only geometric selection mode
-                setCellSet();
+                setCellSelection();
             }
 
             // Report new volume (if changed)
diff --git a/src/fvOptions/cellSetOption/cellSetOption.H b/src/fvOptions/cellSetOption/cellSetOption.H
index 02b2931fdc..0b630e7463 100644
--- a/src/fvOptions/cellSetOption/cellSetOption.H
+++ b/src/fvOptions/cellSetOption/cellSetOption.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2017-2020 OpenCFD Ltd.
+    Copyright (C) 2017-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -126,10 +126,10 @@ public:
         //- Enumeration for selection mode types
         enum selectionModeType
         {
-            smPoints,
+            smAll,
             smCellSet,
             smCellZone,
-            smAll
+            smPoints
         };
 
         //- List of selection mode type names
@@ -138,7 +138,7 @@ public:
 
 protected:
 
-    // Protected data
+    // Protected Data
 
         //- Start time of fvOption
         scalar timeStart_;
@@ -162,13 +162,13 @@ protected:
         scalar V_;
 
 
-    // Protected functions
+    // Protected Functions
 
-        //- Set the cellSet or points selection
+        //- Set cell selection name or points selection from dictionary input
         void setSelection(const dictionary& dict);
 
-        //- Set the cell set based on the user input selection mode
-        void setCellSet();
+        //- Set the cell selection based on user input selection mode
+        void setCellSelection();
 
         //- Recalculate the volume
         void setVol();
@@ -201,35 +201,38 @@ public:
         // Access
 
             //- Return const access to the time start
-            inline scalar timeStart() const;
+            inline scalar timeStart() const noexcept;
 
             //- Return const access to the duration
-            inline scalar duration() const;
+            inline scalar duration() const noexcept;
 
-            //- Return true if within time limits
-            inline bool inTimeLimits(const scalar time) const;
+            //- True if within time limits
+            inline bool inTimeLimits(const scalar timeValue) const;
 
-            //- Return const access to the cell selection mode
-            inline const selectionModeType& selectionMode() const;
+            //- Return the cell selection mode
+            inline selectionModeType selectionMode() const noexcept;
 
-            //- Return const access to the name of cell set for "cellSet"
-            //  selectionMode
-            inline const word& cellSetName() const;
+            //- True if sub-selection should be used
+            inline bool useSubMesh() const noexcept;
+
+            //- Return const access to the name of cell set/zone for
+            //- "cellSet" / "cellZone" selection modes
+            inline const word& cellSetName() const noexcept;
 
             //- Return const access to the total cell volume
-            inline scalar V() const;
+            inline scalar V() const noexcept;
 
-            //- Return const access to the cell set
-            inline const labelList& cells() const;
+            //- Return const access to the cell selection
+            inline const labelList& cells() const noexcept;
 
 
         // Edit
 
-            //- Return access to the time start
-            inline scalar& timeStart();
+            //- Adjust the time start, return the old value
+            inline scalar timeStart(scalar val) noexcept;
 
-            //- Return access to the duration
-            inline scalar& duration();
+            //- Adjust the duration, return the old value
+            inline scalar duration(scalar val) noexcept;
 
 
         // Checks
diff --git a/src/fvOptions/cellSetOption/cellSetOptionI.H b/src/fvOptions/cellSetOption/cellSetOptionI.H
index da6b40d23c..3917f206b8 100644
--- a/src/fvOptions/cellSetOption/cellSetOptionI.H
+++ b/src/fvOptions/cellSetOption/cellSetOptionI.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,19 +28,19 @@ License
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-inline Foam::scalar Foam::fv::cellSetOption::timeStart() const
+inline Foam::scalar Foam::fv::cellSetOption::timeStart() const noexcept
 {
     return timeStart_;
 }
 
 
-inline Foam::scalar Foam::fv::cellSetOption::duration() const
+inline Foam::scalar Foam::fv::cellSetOption::duration() const noexcept
 {
     return duration_;
 }
 
 
-inline bool Foam::fv::cellSetOption::inTimeLimits(const scalar time) const
+inline bool Foam::fv::cellSetOption::inTimeLimits(const scalar timeValue) const
 {
     return
     (
@@ -53,40 +54,50 @@ inline bool Foam::fv::cellSetOption::inTimeLimits(const scalar time) const
 }
 
 
-inline const Foam::fv::cellSetOption::selectionModeType&
-Foam::fv::cellSetOption::selectionMode() const
+inline Foam::fv::cellSetOption::selectionModeType
+Foam::fv::cellSetOption::selectionMode() const noexcept
 {
     return selectionMode_;
 }
 
 
-inline const Foam::word& Foam::fv::cellSetOption::cellSetName() const
+inline bool Foam::fv::cellSetOption::useSubMesh() const noexcept
+{
+    return selectionMode_ != selectionModeType::smAll;
+}
+
+
+inline const Foam::word& Foam::fv::cellSetOption::cellSetName() const noexcept
 {
     return cellSetName_;
 }
 
 
-inline Foam::scalar Foam::fv::cellSetOption::V() const
+inline Foam::scalar Foam::fv::cellSetOption::V() const noexcept
 {
     return V_;
 }
 
 
-inline const Foam::labelList& Foam::fv::cellSetOption::cells() const
+inline const Foam::labelList& Foam::fv::cellSetOption::cells() const noexcept
 {
     return cells_;
 }
 
 
-inline Foam::scalar& Foam::fv::cellSetOption::timeStart()
+inline Foam::scalar Foam::fv::cellSetOption::timeStart(scalar val) noexcept
 {
-    return timeStart_;
+    scalar old(timeStart_);
+    timeStart_ = val;
+    return old;
 }
 
 
-inline Foam::scalar& Foam::fv::cellSetOption::duration()
+inline Foam::scalar Foam::fv::cellSetOption::duration(scalar val) noexcept
 {
-    return duration_;
+    scalar old(duration_);
+    duration_ = val;
+    return old;
 }
 
 
diff --git a/src/fvOptions/corrections/limitTemperature/limitTemperature.C b/src/fvOptions/corrections/limitTemperature/limitTemperature.C
index f47361f012..a96d5d697d 100644
--- a/src/fvOptions/corrections/limitTemperature/limitTemperature.C
+++ b/src/fvOptions/corrections/limitTemperature/limitTemperature.C
@@ -162,8 +162,8 @@ void Foam::fv::limitTemperature::correct(volScalarField& he)
     Info<< type() << " " << name_ << " Unlimited Tmax " << Tmax0 << nl
         <<  "Unlimited Tmin " << Tmin0 << endl;
 
-    // handle boundaries in the case of 'all'
-    if (selectionMode_ == smAll)
+    // Handle boundaries in the case of 'all'
+    if (!cellSetOption::useSubMesh())
     {
         volScalarField::Boundary& bf = he.boundaryFieldRef();
 
diff --git a/src/fvOptions/corrections/limitVelocity/limitVelocity.C b/src/fvOptions/corrections/limitVelocity/limitVelocity.C
index 37f6ccae19..2f8d1003ce 100644
--- a/src/fvOptions/corrections/limitVelocity/limitVelocity.C
+++ b/src/fvOptions/corrections/limitVelocity/limitVelocity.C
@@ -92,15 +92,11 @@ void Foam::fv::limitVelocity::correct(volVectorField& U)
         }
     }
 
-    // handle boundaries in the case of 'all'
-    if (selectionMode_ == smAll)
+    // Handle boundaries in the case of 'all'
+    if (!cellSetOption::useSubMesh())
     {
-        volVectorField::Boundary& Ubf = U.boundaryFieldRef();
-
-        forAll(Ubf, patchi)
+        for (fvPatchVectorField& Up : U.boundaryFieldRef())
         {
-            fvPatchVectorField& Up = Ubf[patchi];
-
             if (!Up.fixesValue())
             {
                 forAll(Up, facei)
diff --git a/src/fvOptions/sources/derived/actuationDiskSource/actuationDiskSourceTemplates.C b/src/fvOptions/sources/derived/actuationDiskSource/actuationDiskSourceTemplates.C
index fdd40cfe70..f51001a7b4 100644
--- a/src/fvOptions/sources/derived/actuationDiskSource/actuationDiskSourceTemplates.C
+++ b/src/fvOptions/sources/derived/actuationDiskSource/actuationDiskSourceTemplates.C
@@ -79,7 +79,7 @@ void Foam::fv::actuationDiskSource::calcFroudeMethod
     scalar rhoRef = 0.0;
     label szMonitorCells = monitorCells_.size();
 
-    for (const auto& celli : monitorCells_)
+    for (const label celli : monitorCells_)
     {
         Uref += U[celli];
         rhoRef = rhoRef + rho[celli];
@@ -150,7 +150,7 @@ void Foam::fv::actuationDiskSource::calcVariableScalingMethod
     scalar rhoRef = 0.0;
     label szMonitorCells = monitorCells_.size();
 
-    for (const auto& celli : monitorCells_)
+    for (const label celli : monitorCells_)
     {
         Uref += U[celli];
         rhoRef = rhoRef + rho[celli];
@@ -175,7 +175,7 @@ void Foam::fv::actuationDiskSource::calcVariableScalingMethod
     scalar rhoDisk = 0.0;
     scalar totalV = 0.0;
 
-    for (const auto& celli : cells_)
+    for (const label celli : cells_)
     {
         Udisk += U[celli]*cellsV[celli];
         rhoDisk += rho[celli]*cellsV[celli];
diff --git a/src/fvOptions/sources/derived/radialActuationDiskSource/radialActuationDiskSourceTemplates.C b/src/fvOptions/sources/derived/radialActuationDiskSource/radialActuationDiskSourceTemplates.C
index d686cde720..037c4ef820 100644
--- a/src/fvOptions/sources/derived/radialActuationDiskSource/radialActuationDiskSourceTemplates.C
+++ b/src/fvOptions/sources/derived/radialActuationDiskSource/radialActuationDiskSourceTemplates.C
@@ -76,7 +76,7 @@ addRadialActuationDiskAxialInertialResistance
     scalar rhoRef = 0.0;
     label szMonitorCells = monitorCells_.size();
 
-    for (const auto& celli : monitorCells_)
+    for (const label celli : monitorCells_)
     {
         Uref += U[celli];
         rhoRef = rhoRef + rho[celli];
diff --git a/src/fvOptions/sources/derived/rotorDiskSource/rotorDiskSource.C b/src/fvOptions/sources/derived/rotorDiskSource/rotorDiskSource.C
index 4c70b9bc15..0f3ade71f0 100644
--- a/src/fvOptions/sources/derived/rotorDiskSource/rotorDiskSource.C
+++ b/src/fvOptions/sources/derived/rotorDiskSource/rotorDiskSource.C
@@ -108,7 +108,6 @@ void Foam::fv::rotorDiskSource::checkData()
                 }
             }
 
-
             break;
         }
         default: