I see the point of the new contributor pop-ups. How about this? "X is an old contributor who has posted here many times. That means: (1) they have given a lot of time and effort to SE and have some reputation here (2) they may know what they're talking about (3) even if they appear grumpy or prickly, it is still best to assume that they are trying to help, if only by signalling that your question is not (yet) easy to understand." No proposals on the threshold reputation for this appearing!

I think that the reputation score itself is intended to convey that information, @NickCox

A reputation of order 1 does also convey information.

@Sycorax A number really doesn't have the same impact as an explicit statement like "<Joe B.> is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct." I think @Nick may be suggesting there is merit in popping up explicit statements for other users, too.