I'd start with setting the combined frecency score to 0 and testing out how the raw fuzzy scoring does. Then if you find you're having trouble finding recent or frequent commands, you can adjust from there. If you can't find a configuration that feels good, please feel free let me know in an issue.
for example, for my second criteria:
> - works on partial matches (e.g. inputting "ma in" matches ("make install", "cd main")
typing "ma in" I would expect "make install" to come before "cd main" to come before (what's currently the very first hit) "cd Binaries/Multimedia".
I'm now reading about https://docs.atuin.sh/cli/configuration/config/?h=fuzzy+daem... while not managing to really get what would seem natural. Sigh.