So practically everything.
Do remember that hitboxes increases the distance of where you can hit players. The same goes for reach. So, if you have a reach of 3.5, and put your hitboxes to 0.04, you can hit players from 3.54 blocks away.
If you can get away with a reach of 3.2, you'll be fine using a reach of 3.1 and hitboxes of 0.1 - it'd be the same thing, except you can hit players a little further when you look a little left/right of them. That's not to say that will bypass - being able to hit players without looking directly at them might cause some flags or automated bans, so be careful with that.
All of that being said, Hypixel doesn't ban for reach. It all just depends on whether or not they actually let the hit - well, *hit* or not. You can legit put reach at 4.5 and use 0.3 hitboxes and not get banned by Watchdog. Though, be careful if you fight someone recording.
I'm unsure of other servers.
Do remember that hitboxes increases the distance of where you can hit players. The same goes for reach. So, if you have a reach of 3.5, and put your hitboxes to 0.04, you can hit players from 3.54 blocks away.
If you can get away with a reach of 3.2, you'll be fine using a reach of 3.1 and hitboxes of 0.1 - it'd be the same thing, except you can hit players a little further when you look a little left/right of them. That's not to say that will bypass - being able to hit players without looking directly at them might cause some flags or automated bans, so be careful with that.
All of that being said, Hypixel doesn't ban for reach. It all just depends on whether or not they actually let the hit - well, *hit* or not. You can legit put reach at 4.5 and use 0.3 hitboxes and not get banned by Watchdog. Though, be careful if you fight someone recording.
I'm unsure of other servers.
Thanks