My only complaint is with the EN-international keyboard my company prefers - there is no way to reverse the tilde key position back to the same place next to 1 on the US keyboard. The OS knows what keyboard the laptop has and refuses to change it.
You can see how I did mine here if you're interested:
https://github.com/bruse/dotfiles/tree/main/macOS (I suspect com.local.KeyRemapping.plist is most interesting, but the key layout file is there too, with some comments on how it was generated).
