This is a full house Reno, so I can do either. Hood is mounted and I’m ready to run the 8” duct for the exhaust. If I go through the ceiling, I’ll have to cut a portion of 2x4 that’s sistered to the ceiling joist to level the old ceiling. No big deal. I have a new roof, and the roofing company will come back and put the cap on anytime. Or, I can simply put an 8” hole in the wall, which has no siding outside; just wrap. I’m not sure if there’s a preference when either is possible.