we have a master and pro diff but not casual i think it could be fun to speedrun

ANY% is played on casual (usually).

yea but i mean saso or sa

Master and Pro routes are almost always identical, and when they aren't it's usually because someone hasn't grinded the Pro route on Master difficulty yet. Casual difficulty will almost have the exact same problem as the route will not change meaningfully at all, and will also certainly lack interest from most runners.