There are zillions of different grades of ally, and many of them will cope with being bent back ten degrees once. Although it might be that hangers tend to be made of something too brittle. This. if it doesn't cause a bunch of little surface cracks, you're good to go, IMO. Even if you get a few tiny ones, the part would almost certainly be strong enough to keep doing its job until it gets bent again.

As an aside, how's this for weird - I have an ally frame that has a stainless hanger. I'm not sure what kind of sense that's supposed to make... in the area around the QR, it's sandwiched between the dropout. Maybe it's got some sort of fancy metallurgy going on whereby it's meant to crack off where it steps out to the width of the dropout, but I can see it more likely causing carnage and defeating the purpose. Odd, no?