Sounds like you’ve got the right idea.
Never knew a coop to have too much ventilation. Just avoid drafts and crosswinds across the roost. Ventilation at the peak shouldn’t cause that problem.
Your build looks fantastic.
I say take the plywood off and repurpose it for the poop boards or whatnot. Then add a furring strip/2x2s to the top of the rafters. Attach the metal roofing to that. Your coop doesn’t have to meet hurricane code. If you’d feel more comfortable you could always add...