Experimenting with those flags again. I created a script which sets flags 0x900-11FF (yeah, I'm am expert at copy and paste, lol) and I found that around var 4250, setting those flags doesn't make a difference 0.o. I'll keep investigating and find out where exactly they do stop having an effect.
Setting all of those flags loses it's effect after var 408F. All of the ones higher (at least up to 4380, I haven't checked any higher) are not affected by setting high number flags.... This is weird.