So, the root issue here is due to a bug in my Ed script, that purchased a spleen skill before purchasing its predecessor. But, KoL seems to have accepted that, and given me the skill. When I did this, KoL credited me 5 spleen limit, but Mafia gave me 10. (The spleen in question was "Yet Another Extra Spleen", purchased before "Another Extra Spleen".) I was able to resolve this by just going to the shop & purchasing the missing skill. But, if it's an easy fix, it might be nice for Mafia's behavior to match KoL's.