I went thru this same issue when I first got my .50
the 2f grouped well but I had to wipe more frequently, tried 3f and found it cleaner burning with more shots before wiping. higher pressure, yes, but not enough to rock the boat. the 2f had a lot less pressure. I mention the .50 merely cause history and the books recommend 2 or 3 in the 50 with 2f the recommened in the .54
alot of folks I shoot with use the 3f in their 54 and also in their pistolas, needing to only carry one powder. If it didnt come out my touch hole, I'd burn 3f in my 62sb.
as has been suggested, try both, find a load combo that groups and go with that!