Minor Action VariableAssignmentExpression seems to ignore the assignment task if a list variable is given as first argument. No exception is thrown, it just does nothing. Since action ASSIGN doesn't operate on list expressions too, it would be great to have this one working here.
See the following example:
DECLARE testType (IntegerArray arr);
INTLIST il;
Document { -> il = {1,2,3}, CREATE(testType, "arr" = il)};