Gaza mats are perfectly ok to use in any situation, you can add an extra floor with them (you really can't add more than one) and really you can't "stack" things much on that extra floor.
That GM needs to do some real work instead of messing with someone's gaza mats. If he needs any help on what, i'll provide him a huge list of things that need fixing. If he's so bored he needs to be a pain with goza mats, maybe we need a new GM.