My main character has a Perception of 16, which while not maxed out, seems pretty decent. However, he was unable to detect the secret described here. I've also read that there's a Gleaming Silver Key on the first floor of the Temple of Ethos, but despite using scout mode and standing on top of where it should be (and wiggling around... and speeding up the game and just waiting) I can't seem to detect any secrets.
Part of the reason I raised perception so high was so that I'd have a good chance of finding secrets, but perhaps I read too much into the Perception tooltip to assume it helps with that. Does mechanics come in to play when it comes to finding secrets? It's tooltip doesn't mention anything, but the answer linked above makes me wonder if that's what I'm missing.
What, exactly, governs whether or not I find secret doors and hidden compartments?