Backporting a datapack

Hello. I very want to backport a 1.20.4 datapack into 1.20.1. This is the Nevermore datapack (or at least most of its modules, I don't care about Jolted). I know that on the surface level, the datapack has no interactions with any features added in the updates, but internal magic may differ. Now this is a massive datapack, and I'm wondering if I am being a delusional individual by seeking to attempt this, given I have close to zero datapack experience. Anyway, how hard can it be? Do I just look at the command format additions and changes on the wiki for 1.20.2 onwards and go through the piles of code, replacing new functions with alternates and that will be dandy? What about NBT files? Also, I'm wondering if there is a way to quickly search for all these commands, or know through any error logs if I missed any when I'm testing in-game. In general, can someone put me on the right track? Any big changes to formatting in 1.20.4 I should look out for? Also I'm going to watch Reacher now and then go to sleep so I'll respond tomorrow.