I just posted my paid ExtraFireworks Minecraft plugin to itch.io too (it's 20% off right now) to test out both, itch.io's purchasing experience and if the platform itself is suitable for non-full games too: https://phoenix616.itch.io/extrafireworks (until now it was only available through SpigotMC.org's premium resource section)
Things I noticed that like already:
- Proper sales!
- Better ability to theme and brand the page
- Payment handled by itch.io
- More metadata like licenses directly in the interface



