No, at least not with a conventional potentiometer. Two Three things stand in your way: 1. The pot must be able to dissipate enough power (0.05*X.X amps). 2. The pot must be extremely low value, we’re talking about a pot that’s has a sweep like 1 ohm to 0.0025 ohm or something. +3. I think that wiring in a pot as a sense resistor could introduce a lot of extra wiring resistance and things and give unexpected results.
Is your interest simply in having a knob to freely adjust brightness, or are you specifically interested in using a potentiometer in place of a sense resistor? If you just want a brightness knob, I did recently start a little bit of work on that. Our discussion in this short thread about the classic Lambda VaraPower driver led me to start hacking up some code. I posted about it in the STAR firmware thread in a small handful of posts strewn between 670 and 715. Most notably #688, #712, and #715.
I’ve set that aside for the moment, but if all you want is a driver which lets you adjust the brightess freely/continuously with a knob then that will be easy. I’m shooting for a driver with LVP which lets you adjust the brightness with a knob.