You can spot HIDs a mile off, so there will be no question IF the tester spots them, he WILL spot them. Now, whether he wants to fail you because of this is up to him, but those are the rules as stupid as they are.
I've passed MOT with a Nismo V2 with no washers, but I count that as lucky since so many people have failed on it. Just google it and look for Lancer Evo forums.