Ah, the disguise command. Back when it was a thing it was a fun and useful command, when 1.8 came the whole plugin was fucked up. I suggest there be a updated version (if it exists) of the disguise command, or a close version of it. I do not know exactly WHY it was removed, but it should be reimplemented into the server.
I'm pretty sure it was removed because of all the glitches. 1.8 made it so that the plugin doesn't work correctly and it probably won't update due to new changes in 1.8. I also had the idea of replacing it with trails. On survival, people gain trails by getting better ranks. I don't see why we don't do the same for creative. For example, builder and constructor don't get any trails. Designer might get 2 trails and engineer might get 2 different trails. Architect could get maybe 5 trails. Something along the lines of that.
There is a plugin called LibsDisguises that supports 1.8 (I have it on my server) Howerver from experience there is one giant glitch: Basically when you are in first-person in a disguise the disguise blocks your view. Which means you have to play in third-person view (F5)
Hmm... is it possible for one to just fix any existing bugs with /disguise, because back when it still existed, i never got to change into anything accept a cow, or sheep.
If the /disguise command was remade, then the OS would have to do some work with it... Even though a lot of people would love for it to return.