Extract Expr: Issue with scoped variable

[#1]

This works:

Extract Expr(:height << set name( "new" ), :height );

But this one doesn't *):

Extract Expr(myDataTable:height << set name( "new" ), myDataTable:height );

Fortunately there is this dirty trick of Extract Expr (it automatically resolves every defined variable **) - which allows this workaround:

x = Expr( myDataTable:height);
Extract Expr(myDataTable:height << set name( "new" ), x )

*) why?

maybe related to (**)?