diff --git a/StandardPlugin/ADAPTParquet.cs b/StandardPlugin/ADAPTParquet.cs
index 5571187..74d19f7 100644
--- a/StandardPlugin/ADAPTParquet.cs
+++ b/StandardPlugin/ADAPTParquet.cs
@@ -14,7 +14,7 @@ namespace AgGateway.ADAPT.StandardPlugin
 {
     internal class ADAPTParquetWriter
     {
-        const int RowGroupSize = 65535;
+        const int RowGroupSize = 65536;
 
         public ADAPTParquetWriter(ADAPTParquetColumnData columnData)
         {    
diff --git a/StandardPlugin/Extensions.cs b/StandardPlugin/Extensions.cs
index 3d96f1d..b6adfcb 100644
--- a/StandardPlugin/Extensions.cs
+++ b/StandardPlugin/Extensions.cs
@@ -239,7 +239,7 @@ public static double HeadingRight(this double heading)
         public static Polygon AsCoveragePolygon(this Point leadingPoint, double width, ref LeadingEdge latestLeadingEdge, double heading, double? reportedDistance, double? calculatedDistance)
         {
             LeadingEdge priorLeadingEdge = latestLeadingEdge;
-            latestLeadingEdge = new LeadingEdge(leadingPoint, width, priorLeadingEdge, heading, reportedDistance);
+            latestLeadingEdge = new LeadingEdge(leadingPoint, width, priorLeadingEdge, heading);
             Point backRight;
             Point backLeft;
             if (priorLeadingEdge != null)
@@ -251,15 +251,16 @@ public static Polygon AsCoveragePolygon(this Point leadingPoint, double width, r
             {
                 //We only consider distance when we don't have a prior point to map from
                 double distance = 1; //1m as default without any other information (at start of data)
-                if (reportedDistance != null)
+                if (reportedDistance > 0d)
                 {
                     distance = reportedDistance.Value;
                 }
-                else if (calculatedDistance != null)
+                else if (calculatedDistance > 0d)
                 {
                     distance = calculatedDistance.Value;
                 }
-                distance = distance > 4 ? 4 : distance; //keep distances sane
+                //Clamp both ends: the floor keeps the back edge off the leading edge, which would make the polygon invalid
+                distance = Math.Clamp(distance, 0.1d, 4d);
 
                 backRight = latestLeadingEdge.Right.Destination(distance, HeadingBack(heading));
                 backLeft = backRight.Destination(width, HeadingLeft(heading));
diff --git a/StandardPlugin/ImplementSection.cs b/StandardPlugin/ImplementSection.cs
index a939446..08dbf3f 100644
--- a/StandardPlugin/ImplementSection.cs
+++ b/StandardPlugin/ImplementSection.cs
@@ -172,10 +172,12 @@ public bool TryGetCoveragePolygon(SpatialRecord record, SpatialRecord previousRe
                 priorPoint = new Point(priorADAPTPoint.X, priorADAPTPoint.Y);
             }
 
+            var sectionDefinitions = FactoredDefinitionsBySourceCodeByProduct[string.Empty];
+
             double bearing = 0d;
-            if (FactoredDefinitionsBySourceCodeByProduct[string.Empty].ContainsKey("vrHeading"))
+            if (sectionDefinitions.TryGetValue("vrHeading", out var headingDefinition))
             {
-                var headingValue = ((NumericRepresentationValue)record.GetMeterValue(FactoredDefinitionsBySourceCodeByProduct[string.Empty]["vrHeading"].WorkingData))?.Value?.Value;
+                var headingValue = ((NumericRepresentationValue)record.GetMeterValue(headingDefinition.WorkingData))?.Value?.Value;
                 if (headingValue != null)
                 {
                     bearing = headingValue.Value;
@@ -194,13 +196,13 @@ public bool TryGetCoveragePolygon(SpatialRecord record, SpatialRecord previousRe
             var xy = x.Destination(Offset.Y ?? 0d, bearing + 90d % 360d);
 
             double? reportedDistance = null;
-            if (FactoredDefinitionsBySourceCodeByProduct[string.Empty].ContainsKey("vrDistanceTraveled") &&
-                record.GetMeterValue(FactoredDefinitionsBySourceCodeByProduct[string.Empty]["vrDistanceTraveled"].WorkingData) is NumericRepresentationValue distanceData)
+            if (sectionDefinitions.TryGetValue("vrDistanceTraveled", out var distanceDefinition) &&
+                record.GetMeterValue(distanceDefinition.WorkingData) is NumericRepresentationValue distanceData)
             {
                 reportedDistance = distanceData?.Value?.Value;
             }
-            double? calculatedDistance = null;  
-            if (reportedDistance == null && priorPoint != null)
+            double? calculatedDistance = null;
+            if (!(reportedDistance > 0d) && priorPoint != null)
             {
                 calculatedDistance = GeometryExporter.HaversineDistance(priorPoint, point);
             }
@@ -220,7 +222,7 @@ public void ClearLeadingEdge()
 
     internal class LeadingEdge
     {
-        public LeadingEdge(Point leadingPoint, double width, LeadingEdge priorLeadingEdge, double heading, double? reportedDistance)
+        public LeadingEdge(Point leadingPoint, double width, LeadingEdge priorLeadingEdge, double heading)
         {
             Heading = heading;
             double wh = width / 2d;
diff --git a/StandardPlugin/WorkRecordExporter.cs b/StandardPlugin/WorkRecordExporter.cs
index 76f467e..f2f846b 100644
--- a/StandardPlugin/WorkRecordExporter.cs
+++ b/StandardPlugin/WorkRecordExporter.cs
@@ -521,9 +521,9 @@ private void ExportOperationSpatialRecords(ADAPTParquetColumnData runningOutput,
                         {
                             if (dataColumn.ProductId != null && section.ProductIndexWorkingData != null)
                             {
-                                if (section.FactoredDefinitionsBySourceCodeByProduct.ContainsKey(dataColumn.ProductId))
+                                if (section.FactoredDefinitionsBySourceCodeByProduct.TryGetValue(dataColumn.ProductId, out var factoredDefinitionsForProduct) &&
+                                    factoredDefinitionsForProduct.TryGetValue(dataColumn.SrcName, out var factoredDefinition))
                                 {
-                                    var factoredDefinition = section.FactoredDefinitionsBySourceCodeByProduct[dataColumn.ProductId][dataColumn.SrcName];
                                     NumericRepresentationValue value = record.GetMeterValue(factoredDefinition.WorkingData) as NumericRepresentationValue;
                                     var doubleVal = value.AsConvertedDouble(dataColumn.TargetUOMCode) * factoredDefinition.Factor;
 
@@ -540,15 +540,22 @@ private void ExportOperationSpatialRecords(ADAPTParquetColumnData runningOutput,
                                 }
                                 else
                                 {
-                                    dataColumn.Values.Add(0d); //We've grouped operations together and this doesn't apply.
+                                    dataColumn.Values.Add(0d); //This section doesn't report this working data for this product (e.g. grouped operations, or not every section reports every column)
                                 }
                             }
                             else
                             {
-                                var factoredDefinition = section.FactoredDefinitionsBySourceCodeByProduct[string.Empty][dataColumn.SrcName];
-                                NumericRepresentationValue value = record.GetMeterValue(factoredDefinition.WorkingData) as NumericRepresentationValue;
-                                var doubleVal = value.AsConvertedDouble(dataColumn.TargetUOMCode) * factoredDefinition.Factor;
-                                dataColumn.Values.Add(doubleVal);
+                                if (section.FactoredDefinitionsBySourceCodeByProduct.TryGetValue(string.Empty, out var factoredDefinitionsForSection) &&
+                                    factoredDefinitionsForSection.TryGetValue(dataColumn.SrcName, out var factoredDefinition))
+                                {
+                                    NumericRepresentationValue value = record.GetMeterValue(factoredDefinition.WorkingData) as NumericRepresentationValue;
+                                    var doubleVal = value.AsConvertedDouble(dataColumn.TargetUOMCode) * factoredDefinition.Factor;
+                                    dataColumn.Values.Add(doubleVal);
+                                }
+                                else
+                                {
+                                    dataColumn.Values.Add(null); //This section doesn't report this working data; missing is not zero
+                                }
                             }
                         }
                     }
@@ -600,7 +607,7 @@ internal string Key()
         }
         internal string ProductKey()
         {
-            return string.Join(";", ProductIds.OrderBy(x => x).ToString());
+            return string.Join(";", ProductIds.OrderBy(x => x));
         }
 
         internal bool IsMatchingOperation(OperationDefinition other)