MatCat:
there is a travel of about 4.8 meters of 22AWG wire, I wonder what that does to resistance and capacitance
At these power levels it might drop half a volt along the wire because of resistance. No biggie, but make sure you have enough overhead in the power supply.
MatCat:
and if it is enough to merit bumping up the total constant current sink to overcome the loss
All you need to worry about is that is has enough volts to play with.