diff --git a/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/CalculationFilterGroup.cs b/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/CalculationFilterGroup.cs
index fb48dc8..4580779 100644
--- a/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/CalculationFilterGroup.cs
+++ b/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/CalculationFilterGroup.cs
@@ -4,33 +4,31 @@ namespace Strata.SqlTools.Snowflake.ExpressionFactory.Query;
 
 public class CalculationFilterGroup
 {
-    [JsonIgnore]
-    private IEnumerable<CalculationFilter> _filters;
-
     // Hereditary logical operation applied to all Filters
     public LogicalOperator LogicalOperator { get; set; }
 
-    public IEnumerable<CalculationFilter> Filters
-    {
-        get => _filters?.Where(x => x.IsValid()).ToList() ?? new List<CalculationFilter>();
-        set => _filters = value;
-    }
+    public IEnumerable<CalculationFilter> Filters { get; set; }
 
     public CalculationFilterGroup()
     {
         LogicalOperator = LogicalOperator.And;
-        _filters = new List<CalculationFilter>();
+        Filters = new List<CalculationFilter>();
     }
 
     [JsonConstructor]
     public CalculationFilterGroup(IEnumerable<CalculationFilter> filters, LogicalOperator logicalOperator)
     {
-        _filters = filters;
+        Filters = filters;
         LogicalOperator = logicalOperator;
     }
 
+    public IEnumerable<CalculationFilter> GetValidFilters()
+    {
+        return Filters?.Where(x => x.IsValid()).ToList() ?? new List<CalculationFilter>();
+    }
+
     public bool IsValid()
     {
-        return Filters != null && Filters.Any();
+        return GetValidFilters().Any();
     }
 }
diff --git a/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/QueryConfigExtensions.cs b/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/QueryConfigExtensions.cs
index fd0c34c..88f72c2 100644
--- a/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/QueryConfigExtensions.cs
+++ b/src/Strata.SqlTools.Snowflake/ExpressionFactory/Query/QueryConfigExtensions.cs
@@ -11,7 +11,7 @@ public static class QueryConfigExtensions
     public static int[] GetAllColumnIds(this QueryConfig queryConfig)
     {
         return queryConfig.Values.SelectMany(value => value.CalculationDataColumnIds)
-            .Union(queryConfig.Values.SelectMany(x => x.FilterGroups.SelectMany(y => y.Filters.Select(f => f.DataColumnId))))
+            .Union(queryConfig.Values.SelectMany(x => x.FilterGroups.SelectMany(y => y.GetValidFilters().Select(f => f.DataColumnId))))
             .Union(queryConfig.Rows.Select(row => row.DataColumnId))
             .Union(queryConfig.FilterGroups.SelectMany(filterGroup => filterGroup.Filters.Select(filter => filter.DataColumnId)))
             .ToArray();
diff --git a/src/Strata.SqlTools.SqlBreakdown/Expressions/InputPropertyExpression.cs b/src/Strata.SqlTools.SqlBreakdown/Expressions/InputPropertyExpression.cs
index 70ae99e..f984759 100644
--- a/src/Strata.SqlTools.SqlBreakdown/Expressions/InputPropertyExpression.cs
+++ b/src/Strata.SqlTools.SqlBreakdown/Expressions/InputPropertyExpression.cs
@@ -1,6 +1,7 @@
 using Strata.SqlTools.SqlBreakdown.Interfaces.Core;
 
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Text.Json;
 using System.Text.Json.Serialization;
@@ -373,6 +374,7 @@ public class HierarchicalData : IHierarchicalData
 
     public IFlatData Data { get; set; }
 
+    [SuppressMessage("Major Code Smell", "S2365:Properties should not make collection or array copies", Justification = "AllChildData is part of the IHierarchicalData interface contract and is JSON-serialized (see Data.json). The flatten-on-get / group-on-set transformation is the deliberate purpose of the property — _childDataMap is the storage form, the property is the wire form.")]
     public IEnumerable<IHierarchicalData> AllChildData
     {
         get => _childDataMap.SelectMany(x => x.Value).ToList();
diff --git a/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/CalculationFilterGroup.cs b/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/CalculationFilterGroup.cs
index ca56ae4..5fb4e0d 100644
--- a/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/CalculationFilterGroup.cs
+++ b/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/CalculationFilterGroup.cs
@@ -4,33 +4,31 @@ namespace Strata.SqlTools.SqlServer.ExpressionFactory.Query;
 
 public class CalculationFilterGroup
 {
-    [JsonIgnore]
-    private IEnumerable<CalculationFilter> _filters;
-
     // Hereditary logical operation applied to all Filters
     public LogicalOperator LogicalOperator { get; set; }
 
-    public IEnumerable<CalculationFilter> Filters
-    {
-        get => _filters?.Where(x => x.IsValid()).ToList() ?? new List<CalculationFilter>();
-        set => _filters = value;
-    }
+    public IEnumerable<CalculationFilter> Filters { get; set; }
 
     public CalculationFilterGroup()
     {
         LogicalOperator = LogicalOperator.And;
-        _filters = new List<CalculationFilter>();
+        Filters = new List<CalculationFilter>();
     }
 
     [JsonConstructor]
     public CalculationFilterGroup(IEnumerable<CalculationFilter> filters, LogicalOperator logicalOperator)
     {
-        _filters = filters;
+        Filters = filters;
         LogicalOperator = logicalOperator;
     }
 
+    public IEnumerable<CalculationFilter> GetValidFilters()
+    {
+        return Filters?.Where(x => x.IsValid()).ToList() ?? new List<CalculationFilter>();
+    }
+
     public bool IsValid()
     {
-        return Filters != null && Filters.Any();
+        return GetValidFilters().Any();
     }
 }
diff --git a/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/QueryConfigExtensions.cs b/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/QueryConfigExtensions.cs
index 7cafd14..692f4a5 100644
--- a/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/QueryConfigExtensions.cs
+++ b/src/Strata.SqlTools.SqlServer/ExpressionFactory/Query/QueryConfigExtensions.cs
@@ -11,7 +11,7 @@ public static class QueryConfigExtensions
     public static int[] GetAllColumnIds(this QueryConfig queryConfig)
     {
         return queryConfig.Values.SelectMany(value => value.CalculationDataColumnIds)
-            .Union(queryConfig.Values.SelectMany(x => x.FilterGroups.SelectMany(y => y.Filters.Select(f => f.DataColumnId))))
+            .Union(queryConfig.Values.SelectMany(x => x.FilterGroups.SelectMany(y => y.GetValidFilters().Select(f => f.DataColumnId))))
             .Union(queryConfig.Rows.Select(row => row.DataColumnId))
             .Union(queryConfig.FilterGroups.SelectMany(filterGroup => filterGroup.Filters.Select(filter => filter.DataColumnId)))
             .ToArray();