Being forced to sneak in a 1.5 blocks high space doesn't prevent you from falling down

Team mojang can add a button in special settings .

Sorry for my English 

Pretty sure this is intentional. Being forced to continue to crawl also makes it lose some sprint swimming aspects such as allowing a sneak animation, but the other quirks are hard to explain. Removing quirks like these will just make the game more complicated than it should be.

It also doesn't prevent foxes and ocelots from running away from you. MC-182043

This would make you get stuck in some circumstances.