Use of derived or direct units when using scripts to test hardware

This is my first stack overflow post and I'm looking for some advice. I've developed a hardware abstracted test framework using generic classes in python, to test some RF hardware.

Some of the hardware I'm testing will report values back different formats, i.e one will report back dBm, and the other ADC counts.

For testing is it better to return units direct from the devices under test, or as these devices are siblings in my class structure and the data is accessed with the same overloaded parent method, should I convert the ADC counts in dBm? This would require some assumptions about input impedances?

Any feedback is appreciated, and I'm sorry if I've posted this in the wrong forum, if so, please direct me to the correct one.

Many thanks,

Daniel