This is not implemented in AcNot, and there is no Set function. There is Get, and CONST_ works both ways.
Not urgent, and I believe that it boils down to the same opcodes, but worth raising.
Although efficiency might rise if Get/Set didn't go through CONST_... Which path did you choose? I'm guessing that it's all running through CONST_ logic, because that requires minimal new code at a cost to efficiency.