I think a godol can be defined as a well known talmid chochom, to whom a great multitude of people turn to for halachik direction.
With that in mind, (at the risk of “outing” myself as a YU alumni) I have to disagree with cantoresq. I know all the personalities you mention. By my definition Rav Shechter fits the bill, but R’ Michael Rosenzweig and R’ Willig? Tremendous talmidei chachomim no doubt, but gedolim? Hardly. By the way, I am embarrassed by the fact that he chooses to go by the name Michael.
Regarding lesschumras, I was going to make the exact point that someone else did…
kocha de’heteira odif. HKB”H gave us 613 mitzvos which are difficult enough to be midakdek in correctly. There is no need to be machmir above and beyond…..
If someone wants to be machmir for himself, fine. But the “chumra of the week” which becomes Toras Moshe in many cases, I think we can do without.