Oh that's hard with Leo. My DS woke really upset when he was put down for an UT nap because he was tired enough to be upset about waking but not tired enough to sleep longer. It really is hard to tell, all but one supporter was telling me he was OT, only one lone voice said UT and that made more sense to me (even though I had no clue where I was up to but it just felt more right).
Sorry, not much help but holding your hand, you are doing so well xx