I don’t have a moonlander but I did get one of their ergodox keyboards after noticing an increase in pain myself. I tried using it in querty and my experience was unless you type with proper hand position and finger movements (and possibly not even then) querty on an orthinear was even more painful than on a regular keyboard. I tried colemak for a while but something about the layout didn’t feel comfortable still. I landed on using “middlemak” [1] which at least for me has been much more comfortable. It preserves a decent bit of qwerty placement to help with muscle memory, but I’ve also found that only using it on the ergodox keyboard and keeping qwerty on all of my “normal” keyboards has also helped the muscle memory a lot.
QWERTY with "proper" hand placement isn't too bad, but I've been typing like this since I was 4 years old and have never tried another layout, so I might just be missing out. Still, it took me more than a year to really get used to the Ergodox... I shudder to think how long a new layout would take to get used to!
[1]: https://www.reddit.com/r/Middlemak/wiki/index/