diff --git a/xo-cmake/cmake/xo_macros/xo_cxx.cmake b/xo-cmake/cmake/xo_macros/xo_cxx.cmake
index ceedc3e2..4872043c 100644
--- a/xo-cmake/cmake/xo_macros/xo_cxx.cmake
+++ b/xo-cmake/cmake/xo_macros/xo_cxx.cmake
@@ -1739,7 +1739,6 @@ function(xo_add_genfacetimpl)
         FACET_DIR           # facet directory (instead of FACET_PKG)
         FACET               # facet name
         INPUT               # Input .json5 file
-        OUTPUT_HPP_DIR      # Directory for .hpp files
         OUTPUT_IMPL_SUBDIR  # Subdirectory name for impl headers
     )
     set(multiValueArgs "")
diff --git a/xo-expression2/CMakeLists.txt b/xo-expression2/CMakeLists.txt
index c457eca8..08f152b2 100644
--- a/xo-expression2/CMakeLists.txt
+++ b/xo-expression2/CMakeLists.txt
@@ -40,7 +40,6 @@ xo_add_genfacetimpl(
     FACET SymbolTable
 #    REPR LocalSymtab
     INPUT idl/ISymbolTable_DLocalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # note: manual target; generated code committed to git
@@ -50,7 +49,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR LocalSymtab
     INPUT idl/IGCObject_DLocalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # note: manual target; generated code committed to git
@@ -60,7 +58,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR LocalSymtab
     INPUT idl/IPrintable_DLocalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # ----------------------------------------------------------------
@@ -72,7 +69,6 @@ xo_add_genfacetimpl(
     FACET SymbolTable
 #    REPR GlobalSymtab
     INPUT idl/ISymbolTable_DGlobalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # note: manual target; generated code committed to git
@@ -82,7 +78,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR GlobalSymtab
     INPUT idl/IGCObject_DGlobalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # note: manual target; generated code committed to git
@@ -92,7 +87,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR GlobalSymtab
     INPUT idl/IPrintable_DGlobalSymtab.json5
-    OUTPUT_IMPL_SUBDIR symtab
 )
 
 # ----------------------------------------------------------------
@@ -115,7 +109,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR Constant
     INPUT idl/IExpression_DConstant.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -125,7 +118,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR Constant
     INPUT idl/IGCObject_DConstant.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -135,7 +127,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR Constant
     INPUT idl/IPrintable_DConstant.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -147,7 +138,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR Variable
     INPUT idl/IExpression_DVariable.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -157,7 +147,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR Variable
     INPUT idl/IGCObject_DVariable.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -167,7 +156,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR Variable
     INPUT idl/IPrintable_DVariable.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -179,7 +167,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR Typename
     INPUT idl/IGCObject_DTypename.json5
-    OUTPUT_IMPL_SUBDIR typename
 )
 
 # note: manual target; generated code committed to git
@@ -189,7 +176,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR Typename
     INPUT idl/IPrintable_DTypename.json5
-    OUTPUT_IMPL_SUBDIR typename
 )
 
 # ----------------------------------------------------------------
@@ -201,7 +187,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR VarRef
     INPUT idl/IExpression_DVarRef.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -211,7 +196,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR VarRef
     INPUT idl/IGCObject_DVarRef.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -221,7 +205,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR VarRef
     INPUT idl/IPrintable_DVarRef.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -233,7 +216,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR DefineExpr
     INPUT idl/IExpression_DDefineExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -243,7 +225,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR DefineExpr
     INPUT idl/IGCObject_DDefineExpr.json5
-    OUTPUT_IMPL_SUBDIR define
 )
 
 # note: manual target; generated code committed to git
@@ -253,7 +234,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR DefineExpr
     INPUT idl/IPrintable_DDefineExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -265,7 +245,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR ApplyExpr
     INPUT idl/IExpression_DApplyExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -275,7 +254,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR ApplyExpr
     INPUT idl/IGCObject_DApplyExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -285,7 +263,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR ApplyExpr
     INPUT idl/IPrintable_DApplyExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -297,7 +274,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR LambdaExpr
     INPUT idl/IExpression_DLambdaExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -307,7 +283,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR LambdaExpr
     INPUT idl/IGCObject_DLambdaExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -317,7 +292,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR LambdaExpr
     INPUT idl/IPrintable_DLambdaExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -329,7 +303,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR IfElseExpr
     INPUT idl/IExpression_DIfElseExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -339,7 +312,6 @@ xo_add_genfacetimpl(
     FACET GCObject
 #    REPR IfElseExpr
     INPUT idl/IGCObject_DIfElseExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -349,7 +321,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR IfElseExpr
     INPUT idl/IPrintable_DIfElseExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------
@@ -361,7 +332,6 @@ xo_add_genfacetimpl(
     FACET Expression
 #    REPR SequenceExpr
     INPUT idl/IExpression_DSequenceExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -370,7 +340,6 @@ xo_add_genfacetimpl(
     FACET_PKG xo_alloc2
     FACET GCObject
     INPUT idl/IGCObject_DSequenceExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # note: manual target; generated code committed to git
@@ -380,7 +349,6 @@ xo_add_genfacetimpl(
     FACET Printable
 #    REPR SequenceExpr
     INPUT idl/IPrintable_DSequenceExpr.json5
-    OUTPUT_IMPL_SUBDIR detail
 )
 
 # ----------------------------------------------------------------