Final Fantasy Hacktics

I've been using Bcrobert's Nightmare Modules to edit some small mission data to smoothen out "challenge runs". However, I realized there's no data for changing a mission's class requirement (like Soldier for Dueling Sub). Anyone knows how I could edit this?

I've done some looking around in the mission data extract nmm (as opposed to the regular mission data nmm) and the most significant I found were fields 6 and 58 which in my testing sample of dispatch missions without a class requirement always have as values 15 and 00 respectively, but I'm unsure they're the right values as I fail to find a correlation when comparing missions that do require a specific class (Dueling Sub requiring Soldier has 02 and 08 respectively, Sprohm Meet requiring Fighter has 10 and 18 respectively, and Run For Fun requiring Juggler has 08 for both).

And I have 1 more question also about missions: does anyone know how to set the Monster Bank requirement of Fiend Run to 0?

EDIT: OK, so I've discovered setting both fields 58 and 59's values to 00 removes any class requirement (only field 58 is not sufficient). However, even missions without class requirements have varying values for field 59, so that's weird. Would anyone know if I'm breaking something by doing this?