I wasn't sure how to contact you so I figured I'd just hit you in an issue. I have your mod updated for 1.21.6 if you haven't started on it yet. Tested and fully working but I'm waiting to submit the PR when parchmentmc publishes their 1.21.6 version as I compiled it with an experimental 1.21.6-pre1 version of parchment. If you have a discord, I'd love to be able to communicate with you. My discord name is the same as here. I like helping busy people out on updating mods when I'm not busy, and your mod is one of my dependencies so there was something in it for me as well lol. Feel free to close this "issue" when you've read it

Hello! Nice to hear that you already did some work re the update! I probably won't have time to look into the updating process (also for my other mods) for the next 3 weeks because of exams, so feel free to open the PR once Parchment has updated (or you can use the 1.21.5 version of Parchment, that works too), I'll take a look at it when I have time.
In the meantime, feel free to contact me on discord should the need be: I don't really know if you can search for anyone's name on discord, if so, my name is "redstone_dubstep". If not, I should be in plenty of other Discord servers like the NeoForge/Parchment official ones.
I'll close this issue for now, and will be awaiting your PR. ;-)