Well we have several things going on here so... On the base of the bullet. I think it ought to be flat. I think there is a feeling a flat base is most accurate. The Minnie Bullets with the hollow base- that was so they could load easy in a musket and the idea was the walls of the base would expand for a good gas seal. On a revolver with a cylinder gap- I'm not sure one way or the other if a hollow base would be beneficial. The purpose of a thin wad- if one was used, I figured to push any fouling out the barrel. One of Sam Colt's original patents had a conical bullet with a very thin cork wad but the design was dropped so maybe a wad isn't needed or useful. On bullet design, the ramrod has a way to twist the point of the bullet out of line. A wide band on the bullet ought to help, so a bullet that mostly tapers to the base, with a narrow band just at the base, that would be more likely to twist out of line.
I have shot both out of a Colt Navy, The conical bullets are in a combustible case and I shoot 100 at a session but I've never noticed lead fouling. The round balls I use a lubed wad and again never notice fouling. I never fill the chamber ends with grease/Crisco. I think we might be over worried on lead fouling.
We also have the issue of the forcing cone. On a modern revolver some guys re-cut the degree to a more gentle slop and claim it improves accuracy. I have no idea if the same thing would help with a percussion. If you are using round balls I think they would tend to allign themselves, not like a semi-wadcutter on a modern revolver.