Vent covers are installed, no problems, pretty easy to do. I used a 3' x 2' piece of plywood to lay on when needed and it worked fine. I did disassemble the fan tastic vent fan for cleaning and to make sure I didn't drill into anything when attaching the vent cover brackets.
No problems encountered other than the 95 degree heat while laying on the roof!
I was ready to finish when I did.