I prefer .380 for every .36 cap gun, but only have one (a custom gun with honed chambers) which requires them. I have often used .375 in Uberti revolvers; it has never caused any problems for me.
The one good point for a shaved lead ring is that it provides visual evidence that a proper seal has been made. I have some guns that will cut a ring and others that swage the ball down. As long as the ball seals the chamber, I don't much care either way.
I'm another who suspects most chainfires originate at the cones, but I'm no longer confident enough to say that they can't happen at the front. It may even be possible that topping the ball with grease can prevent chainfires - but if it can, I'd argue that something else is wrong, and that the lube is a band-aid. Certainly, blowing great gobs of grease all over everything keeps the gun lubed and the fouling soft. I personally hate the mess it makes, but to each his own.
So I just dump in a charge, cover it with a Wonder wad, ram home a .380 if I've got one and a .375 if I don't, cap, and fire. In a properly tuned gun, that's all it takes, and the gun will run until the end of time.