On the top hat vs airtime hill debate, I think - for me - what classifies something as a top hat is not so much the verticality, but more the twisting involved in the incline/descent.
I reckon it would've been the now-dead top hat on the two S&S airlaunches as apparently you got some deadly ejector on those, plus 90 degrees up and down. Whether or not this can be classified as an 'airtime hill' might be up for debate... but it's a hill that provides airtime.
So yeah, I'd be of the view that these were airtime hills, not top hats. But I guess on this front, it's kinda splitting hairs, and can be argued to not be a "pure airtime hill".
There's certainly no park that has claimed to have the 'steepest airtime hill', I guess in part because it's a very obtuse claim to make, and 'steepest' probably isn't the correct word. So no way to confirm directly in that sense. I think Kondaa is a really good shout if we're ignoring verticality.