Almost any fan can deal with angled ceilings. The question is whether the adapters a specific fan will fit the angle of your ceiling. That's best answered by talking to a dealer or calling the manufacturer and having the specs for your situation in hand.

Sounds like you have a steep pitched roof.

Yeah, well, I called Hunter directly and they said their adapter would fit up to a 45 degree angle and it didn't work. (We have a professional installer, fwiw). I was hoping for some BTDT advice.

It's all but impossible to give specific advice given the limited description. OK, you called Hunter, but did you also call Minka, Savoy and Casablanca and provide specifics about the installation? You have a professional installer so why don't you let that person pick the right hardware.

Better yet, go to a fan store, use their expertise to select an appropriate fan and hardware and perform the installation. Sure it will cost a bit more but but will get done right the first time and you won't be spending endless hours buying and returning hardware that doesn't fit.