f17r

[MarcoP]

Perhaps, "mallior" could be a valid word form of "malo"?

Doubt it. It is more likely to be an old spelling of mayor, "greatest" or "oldest", etc etc- ll and y were often confused. Or even mejor, "better", although then i would expect mehor.

I agree.
For "malo" as a form of the verb malle, see You are not allowed to view links. Register or Login to view..
The adjective "malus" (bad) is irregular and its comparative is "peior" (worst), not the "expected" "malior"

This suggests another possibility: could the second letter be an "u" corrected into an "o": You are not allowed to view links. Register or Login to view. (Latin: softer)?
Or You are not allowed to view links. Register or Login to view. (old French from Latin "mulier" -woman-).