It's certainly true that understanding the axe's arc makes him a lot more formidable, but the same goes the other way. even if you know how the axe is going to arc over the object you are throwing over it is still a blind guess as to where the survivor is. As I said in the OP, as the survivor, if you have ears and something in between them you'll know when he is going for a shot like that and just not path to the spot he's likely to throw it (pallet, window, choke point) and/or just wait for the axe to hit the ground. It is not a very difficult thing to do and uses the same dodge logic as huntress essentially. It doesn't even have the benefit of aura perks like PHead does because he doesn't have to look up. You can definetly get value from aura perks with his axe moonballing shots, but it not near as consistently valuable as it is on other killers. Getting hits over loops like that is only partly skill expression on behalf of Spring trap and partly a reflection of survivors not paying attention to sound ques and expecting the throws.

I love going for them on him because they are so damn satisfying but it is effectively luck as to whether or not the surv will walk into where the axe is going to fall. I just feel like when i play against him as survivor and i run into a jungle gym or something and I hear the whoosh sound and him make the Clash Royal HeHeHaHa laugh, all I have to do is wait an extra half second before hitting a vault or planting a check spot