Just to let everyone know, /display head and /display mh are still broken even though you can technically get them to work. The command should function as normal by using /display head off or /display head on, NOT 0 and 1. This bug was not mentioned anywhere in the patch notes so there's no way it was intentional. I'm also led to believe it's a bug because 0 and 1 are boolean values, where 0 represents false and 1 represents true. They are commonly used in programming. Sure, they make sense when you think about it, but from a functionality standpoint it could be confusing for some people.

So, since this is obviously a bug, if GMs could report it that would be great ^^