Powered roof vent question

[BUSBOZO]

My idea is to put a Elixir powered roof vent above the shower for 2 reasons:

1. When vent dome is opened it will provide some light in the shower
2. Vent the steam from the hot water outside.

My shower is located toward the side wall and comes out 32" which put its right under the curved part of the roof. Would I still be able to mount the vent on the curved area? Would a trim ring fit also?

I just don't want to go cutting a 13" hole in the roof and find out it won't sit right.

Would like to see a few examples if anyone has them.

Thanks
Dan