I thought Sardonyx forcing them to test whether they had every other fusion's powers was a little obvious and nonsensical: Sardonyx doesn't have any of the other fusions' powers, after all. (Apparently her ability is rotating her body very freakily?) So that started to wear down the enjoyment of the meta, less in a "I'm uncomfortable along with Smoky Quartz because this is uncool" way (though it was that to start) than a "this is not really working as characterization" way.
I did like that Sardonyx eventually realized what she was doing and felt terrible, but I would've liked an actual apology for that, you know, and a little more underlining that Steven and Amethyst's fusion power wasn't inferiority or insecurity, but fun and unpredictability.
I thought Garnet saying she couldn't ask was a joke about future vision and spoiling the surprise for herself, but apparently it's more meta than that: Garnet canonically never asks questions, per this interview that the AV Club commenters linked to.
Finally, of course fusions have their own rooms in the temple, because Garnet has one, and yet it seemed surprising still.