Why would that be per profile filtering? Hmm. You meant like the maturity settings on Steam, probably. Do they have tag filtering as well for a profile? I know they have an ignore button for games.
For recurring searches you can use bookmarks. (You still need to be logged in for that exclude thing to work)
https://itch.io/games/tag-3d?exclude=tg.low-poly
But that is still over 100k games. https://itch.io/games/tag-3d/tag-low-poly is 15k games, while 3d is 130k.
Maybe in the nieche you are regularly visiting they are more common. The problem is, that the ?ex... string gets lost every time you change the positive tags. And that's what my extention does. Iirc I made the extension to work with ff, but getting unsigned extensions to run on ff is a hassle. Bookmarks are easier. Just make a bunch of them, if you filter the same things often.
Personally I favor individual filtering by games, not tags. I made a tampermonkey script for that, and this works on any browser that can run the tampermonkey extension. It would work super effective in a small nieche you regularly visit. You would also be able to mark games you already tried. Something you cannot do with tag filtering.
It works like this: configure the script, hover mouse over game, press key, game disappears.