This should fix issues such as #341

Apparently, Dope_ZeroFTW14 seems to have some setup where with certain permissions its working? Id like to investigate this to find out the cause, though looking inside the vanilla code the only way to bypass it is to either convince the player it is not inside a portal which I dont believe its possible

Other routes would be

• have the entity unable to change dimensions (though this is hard coded client side for the relevant check)
• Have the entity riding another entity
• Have an entity riding it
• Have the portal on cooldown (can be set via nbt though would likely need to be on spawn or a respawn packet like with the skin changes.)
• Teleport the player out of the nether portal block before triggering the GUI (most servers seem to do this but it seems like it could be annoying)

Tested the portal cooldown, seems the client ignores that.

There doesn't seem to be a point is seeing if we can test "have the entity unable to change dimensions" as its hard coded for player entities.

Will test others though riding an entity seems annoying, being ridden by an armour stand seems best.

https://bugs.mojang.com/browse/MC-2071 see this for evidence that its expected vanilla behavior. We can try the work arounds though :)