I can confirm that the Max Exp option didn't work on Horror Kid. I assume it won't work for Tetra and King Daphnes, too.
I have another question: Do you know the base stats of the Level 4 weapons and how to insert them into a hex editor?
I always wrote FF FF which gives me that whopping 98000 or so, but still I don't One-Hit-Kill anything. Could it be that the strength rolls over
when you put in a too high number? Or are the HP of the enemies always scaled to the strengths of weapond and characters?