I would probably do what was described only for an instance like Hexbear, Lemmygrad, or the one alt-right troll instance on Lemmy. One where nothing good really comes out of being with them. Instance blocks can keep their communties and posts out of my feeds, and I'd definitely do that, but if I want to keep their trolling and emoji spam out of my comments, there isn't exactly a better way to do it. Having an instance manually ban me isn't something I'd do for any ordinary instance, it has to be an extremely troublesome one, like the ones I mentioned.
I know that some people get along great in places like hexbear, but for me they've just been confrontational to me on my main.
I don't know, I thought that maybe it could cause issues since some remote servers might feel insulted or upset by such a request being made to them, and they might get upset at my home instance for it. I don't know how likely it is, and whether or not admins might blame the user for starting such a conflict.
I'm thinking the servers I might do it for will very likely start trouble over it. I wouldn't be looking to do this if they were calm and rational servers (yes one of them is Hexbear).