The exact same reason why I'm sticking with my 32x32 tiles as well, it's so much easier when you can just add that specific item/monster yourself. The blessing of roguelike genre is that we can get away with this, without being pixel art masters :D.
Does that mean you need to go over autotiling all over again? Or you got that thing covered?
Also, why does it say "One Man Army: Unius Exercitus" at the top? Is the name going to change soon?