Feature request - modbus, signed values

[rehor]

Hello, we are using tiny control 3.9 to read few modbus values from a power supply. When reading 16bit values, its always interpreted as unsigned. Would it be possible to add a toggle in custom value definition that would apply conversion to signed integer? There is a way to do it in our graphing system, but the energy calculation on tiny control is not working properly (when the read current is negative).

Please excuse the repost if this issue has been raised already.
Thanks