Not a grammer and punctuation website, but it helps when trying to understand what someone is saying. Never was a fan of the stuff myself, but its funny how clarity happens when you use it properly.
There is nothing inherent in big cups that turns wedding bands into ugly.
But I'm still not clear on much of your meaning. When you say jumbo are you talking gas lense cups or just larger than would be the case with smaller torches?
Did you change tungstn size?
Filler feed rate? (common suckback issue)
Travel speed? (common suckback issue)
Manual manipulation?
Torch angle?