I think expert belt would be a good addition to the "Other" section for items. Quite a few mons use it, like Infernape, latias, jirachi, mixed flygon (although I personally hate using it over life orb on it), and I've even some people use it on mixed tyranitar. If I were to add expert belt to the other items list my list would go something like this
Expert belt:
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I think Ebelt mixed tar has potential but i wanna see more results from it before I move it in front of the slash.
I also think shaymin should be moved behind the slash for all of its roles given how badly it's fallen off. It's not unviable but it's really hard to make work in the current meta.
Scizor I also think should be moved in front of the slash for life orb users. It's life orb SD set rocks and, imo, is it's best set rn. It plows through so much and makes for a great late game cleaner, all while proving a good counter to tyranitar and solid check to latias. It also is a great revenge killer to dd tyranitar, and it can revenge kill dd dragonite in a pinch
Although it is niche and tbh is overall a bad mon, I think umbreon is worth considering adding to wish users, pursuit users and clerics. it does very well vs gengar, it can provide heal bell support to itself and its teammates, and is good at slowing chipping starmie and lati with pursuit. It compresses a lot of roles and in general is really bulky. I would definitely have it be behind the slash though, since its incredibly niche and still is really mediocre and passive. I've only seen it on a couple of very specific teams. It does have a legitimate niche though