And it would take a lot of violations to get you banned for using hitboxes, which is probably why people think hitboxes bypass fine since it takes ages to actually get banned for them (assuming they haven't removed hitbox checks for whatever reason).Hitboxes are made to expand the hitboxes of players. So it means if you're trying to hit outside of the hitbox, it will hit players.
However, looking at the player's hitboxes will behave as a reach, not as hitboxes. And Hypixel blocks hits above 4.25 blocks, so if you're not banned it's normal, since it's not meant to be auto-banned.