Yeah. The one I can't forget is when I mentioned Maglor had a dog in one of my fics. Someone immediately sent me to a fic they'd written because their author note quoted a bit from Lays where after Huan left, no hound would follow Celegorm... and they'd broadened it out to mean no dog would follow any Fëanorian ever again. And my in-head reaction (as opposed to the polite "it just says hounds and Celegorm, I wouldn't broaden that and don't take HoME as canon anyway") was a "why was bringing it up even necessary? Did you mean to make me feel bad for not knowing that tidbit or were you trying to change my mind? We were talking about dogs in fics, not anything deeper!"

Yes. As long as the story makes sense, why should it matter whose father Gil-galad is or hair color or balrog wings or whatever else?