[arp242]

You can store 255 values in one byte, and reserving two bytes is not what that did.

And even if I did, it still leaves the inability to actually rename enums without scanning the full table at least twice (which still doesn't seem possible in MariaDB, unless I missed something there).

If you potentially want great flexibility you shouldn't be using enums in the first place but int and a relational mapping to another table.