diff --git a/engine/table/src/main/java/io/deephaven/engine/table/impl/partitioned/PartitionedTableImpl.java b/engine/table/src/main/java/io/deephaven/engine/table/impl/partitioned/PartitionedTableImpl.java
index 01d180c4d6d..d0ef7a4e850 100644
--- a/engine/table/src/main/java/io/deephaven/engine/table/impl/partitioned/PartitionedTableImpl.java
+++ b/engine/table/src/main/java/io/deephaven/engine/table/impl/partitioned/PartitionedTableImpl.java
@@ -297,9 +297,7 @@ public PartitionedTable transform(
             // Perform the transformation
             final Table resultTable = prepared.update(List.of(new TableTransformationColumn(
                     constituentColumnName,
-                    maybeReplaceExecContext(executionContext), // THIS ONE MUST NOT HAVE THE SAME OT AS THIS CURRENT
-                                                               // THREAD's EXEC CONTEXT,
-                    // UNLESS NON_PARALLELIZABLE
+                    maybeReplaceExecContext(executionContext),
                     prepared.isRefreshing() ? transformer : assertResultsStatic(transformer))));
 
             // Make sure we have a valid result constituent definition
@@ -321,6 +319,12 @@ public PartitionedTable transform(
         return resultPartitionedTable;
     }
 
+    /**
+     * Ensures that the returned executionContext will have an OperationInitializer compatible
+     * with being called by work already running on an initialization thread - it must either
+     * already return false for {@link OperationInitializer#canParallelize()}, or must be a
+     * different instance than the current context's OperationInitializer.
+     */
     private static ExecutionContext maybeReplaceExecContext(ExecutionContext provided) {
         if (provided == null) {
             return null;
@@ -370,9 +374,7 @@ public PartitionedTable partitionedTransform(
                     .update(List.of(new BiTableTransformationColumn(
                             constituentColumnName,
                             RHS_CONSTITUENT,
-                            maybeReplaceExecContext(executionContext), // THIS ONE MUST NOT HAVE THE SAME OT AS THIS
-                                                                       // CURRENT THREAD's EXEC
-                            // CONTEXT, UNLESS NON_PARALLELIZABLE
+                            maybeReplaceExecContext(executionContext),
                             prepared.isRefreshing() ? transformer : assertResultsStatic(transformer))))
                     .dropColumns(RHS_CONSTITUENT);
 
diff --git a/engine/table/src/main/java/io/deephaven/engine/updategraph/impl/PeriodicUpdateGraph.java b/engine/table/src/main/java/io/deephaven/engine/updategraph/impl/PeriodicUpdateGraph.java
index 5efe37a20b3..acc4ea026ee 100644
--- a/engine/table/src/main/java/io/deephaven/engine/updategraph/impl/PeriodicUpdateGraph.java
+++ b/engine/table/src/main/java/io/deephaven/engine/updategraph/impl/PeriodicUpdateGraph.java
@@ -1212,7 +1212,7 @@ public Builder numUpdateThreads(int numUpdateThreads) {
 
         /**
          * Sets a functional interface that adds custom initialization for threads started by this UpdateGraph.
-         * 
+         *
          * @param threadInitializationFactory the function to invoke on any runnables that will be used to start threads
          * @return this builder
          */
diff --git a/engine/updategraph/src/main/java/io/deephaven/engine/updategraph/OperationInitializer.java b/engine/updategraph/src/main/java/io/deephaven/engine/updategraph/OperationInitializer.java
index 84317389a9f..d5d4337e292 100644
--- a/engine/updategraph/src/main/java/io/deephaven/engine/updategraph/OperationInitializer.java
+++ b/engine/updategraph/src/main/java/io/deephaven/engine/updategraph/OperationInitializer.java
@@ -4,7 +4,7 @@
 import java.util.concurrent.Future;
 
 /**
- * alt naming: OperationParallelismControl?
+ * Provides guidance for initialization operations on how they can parallelize.
  */
 public interface OperationInitializer {
     OperationInitializer NON_PARALLELIZABLE = new OperationInitializer() {
@@ -26,21 +26,17 @@ public int parallelismFactor() {
     };
 
     /**
-     * @return Whether the current thread can parallelize operations using this OperationInitialization.
+     * Whether the current thread can parallelize operations using this OperationInitialization.
      */
     boolean canParallelize();
 
     /**
      * Submits a task to run in this thread pool.
-     * 
-     * @param runnable
-     * @return
      */
     Future<?> submit(Runnable runnable);
 
     /**
-     *
-     * @return
+     * Number of threads that are potentially available.
      */
     int parallelismFactor();
 }
diff --git a/props/configs/src/main/resources/dh-defaults.prop b/props/configs/src/main/resources/dh-defaults.prop
index d8276ae33b9..be2dcba5eb9 100644
--- a/props/configs/src/main/resources/dh-defaults.prop
+++ b/props/configs/src/main/resources/dh-defaults.prop
@@ -60,7 +60,3 @@ client.configuration.list=java.version,deephaven.version,barrage.version,http.se
 # jar, and a class that is found in that jar. Any such keys will be made available to the client.configuration.list
 # as <key>.version.
 client.version.list=deephaven=io.deephaven.engine.table.Table,barrage=io.deephaven.barrage.flatbuf.BarrageMessageWrapper
-
-
-# Specifies additional setup to run on threads that can perform table operations with user code. Comma-separated list, instances must be of type io.deephaven.util.thread.ThreadInitializationFactory
-thread.initialization=
diff --git a/props/test-configs/src/main/resources/dh-tests.prop b/props/test-configs/src/main/resources/dh-tests.prop
index 64dfddae10a..f7d2503aa35 100644
--- a/props/test-configs/src/main/resources/dh-tests.prop
+++ b/props/test-configs/src/main/resources/dh-tests.prop
@@ -102,4 +102,3 @@ client.version.list=
 authentication.anonymous.warn=false
 
 deephaven.console.type=none
-thread.initialization=