Rafa Yadein
I want to make it clear that we’re talking about the additional rafa yadein after the start of salat. It can be classified as optional because reportedly prophet SAW has done it sometimes. Evidence should be inquired about from those who categorize it differently. For it to not be a sunnah, the evidence has been given in my above referenced post.
I think ijma doesn’t mean 💯% of the people do it. It just means overall most people do it