I went down that path 10 plus years ago. When I was writing my first book, my fingers got really sore.

I built (two) ErgoDox(en) and ended up using the Norman layout with various attempts at layers over the years. I'm now using a Lily58 with low-profile choc switches that I'm generally happy with.

I'm fine switching back to Qwerty keyboards, but if I were to go down the path again, I would advise myself to stick with Qwerty. I still have a pretty crazy keyboard layout and appreciate the ergonomic features.

Also, I've realized that everyone is different, and what works for one might not work for someone else.

Advice that I think works for everyone is to listen to your body. If your body is telling you that something isn't right, take steps to address them.