When I try to unequip the elytra I can't because the menu of accessories no show it when I click on the accessory button:

Version used
Version: Forge 1.21-51.0.33
Mod version: ohmega-1.2.2+forge-1.21-1.21.1.jar

I recently fixed a bug to do with this on servers only, but it should be working fine.

Edit: I have fixed the bug, it seems to have gotten past testing. I have archived the previous 1.2.2 versions and re-released, I will provide download links below. Sorry about this, but thank you for reporting as I had trouble replicating the bug myself, turns out I had already fixed it on 1.2.2 ports 1.20.4 and below, so it only affected 1.20.6 and above, including the version you were using.

New download links:

• CurseForge
• Modrinth