I completely agree with swordpeddler on this. I personally think the RPG Supplement category, where we can list supporting materials (so we don't have to list them as books/physical games), is the biggest thing on my wishlist. For example, I recently published Wacky Plot Hooks (https://zeshio.itch.io/wackyplothooks), which is like a 10 page supplement with adventuring ideas for people playing roleplaying games. It really doesn't fit anywhere at the moment, and expanding and defining the physical game category like swordpeddler mentions would be a dream for me.
Also, considering the indie ttrpg creator community has been growing year over year, I think making these changes will make the site a lot more friendly. I know a lot of people that feel like they're not getting represented/paid well on the other major marketplaces- and I think this would help everyone involved (itch and creators).
I appreciate your effort in this!