Yeah removing the parity byte in bip340 key serialization certainly made life .. interesting :) There's a whole section of bip327 https://github.com/bitcoin/bips/blob/master/bip-0327.mediawiki to deal with this. I even wrote a function named with a nerd joke about it :) https://github.com/AdamISZ/pathcoin-poc/blob/b9e5021cdce5d394ab170068584ff20c265baf23/pathcoin.py#L97

Your tool seems like a very good idea to help you debug if you're trying to work out a new protocol, it's quite confusing. 

 A very relevant thread; if anything it's notable just because it's long:

https://github.com/jonasnick/bips/issues/32