Personally I don't really think that students transforming in classes is a really big issue, I've never come across it. Plus, magic is disabled in most classes except for flying/dueling. Therefore, I don't think the issue really comes up very often. However, if students start transforming in class, then maybe it could be added to the professor wand.
As for the server in general, I really can't see it being used for reasons other than trolling people who are transformed. Yes, it might be used in roleplay every once and awhile, but I think it would mainly just be used to troll people who transform. It would be annoying for people to keep being transformed back to their human form when they want to transform into their transformo, especially if they spend money on transformos in the store and then it keeps getting canceled by people using this spell :,).
Overall, I think this spell is really cool as it's in the actual HP universe, but I don't really think it would work on Potterworld and would probably be pretty hard to implement.