The answer to this is no, this isn't possible. How frustrating.
Several suggested unbending the 90 degree wall completely and then adding in an 85 degree bend. I did try that, but didn't have any luck getting it to work. Perhaps with some more attempts I would have gotten there, but I gave up.
I managed to workaround my situation and get what I needed, but a simple partial unbend would have made it so much easier.