@mrclose Your 'patch' is improper, and will likely fail.
At least it would here.
Personally, I would lay a steel roof right over the whole mess, and quit worrying about the patch at all.
A steel roof would be more durable to impact, is fire resistant, requires no prep, and is more reparable if in fact damage does happen again (just replace the affected panel).
If you do this buy a few spare sheets, as color matching is a problem over years... But even so, the solution is still easy to repair with any industrial DTM paint (you might have to paint the roof), worst case scenario.
As to repairing what you have:
I would fix the sheathing from below by using a hole saw to create a proper plug, affixed with a slat to put it where it needs to be, and filling around it with an epoxy filler. Remove the slat once the epoxy is dry enough to hold, and repeat the process for the areas that were made inaccessible by the slat. Sand with a palm sander to clean it up as much as possible once the epoxy is fully cured.
Fixing the three-tab roofing is a tricky business that takes a knack.
preferrably on a hot day, when the roofing will be more pliable, you use a flat bar (wonderbar) from underneath the affected tiles and those around it, to pry out the nails, lifting the tile and the nails. any 3-tab thus treated will need to be replaced.
Clear about 3 ft across the patch site, fix the top side of the hole, sand, and paint with an oil primer...
Cut a piece of felt to replace the removed felt in the exposed area, well beyond the hole's edges - say a foot in every direction, making certain the bottom edge of the felt is on top of the lower tabs... But not to the degree that it will show.
Then weave the new 3-tab tiles into place, starting from the bottom and working your way up the patch. The uppermost edge, and the sides where the weaving is occurring is the tough part... the good tiles must be pried up enough to allow them to be out of the way enough to nail on the repair pieces without disturbing the nails or breaking the non-repair tiles... Hence the need for a hot day, so the existing tiles will be as pliable as possible. If the roofing is too brittle to do so (which it will be at about half it's life), patching is not possible.
The existing tiles will look disturbed at first on the finished roof - Give em time, and they will lay back down. you can attempt gluing using a roofing tar/ glue to force the process, but they will lay back down eventually regardless.
On a thing that small, I would rather just remove, and re-roof that side. And if the roofing is off, the damaged plywood can just be replaced. No weird fix in the plywood, no break in the felt, and fresh roofing. All of which is a far more guaranteed process, with a predictable outcome.
Then the felt has no seam, you have no worries about exactly matching the 3tab (which you won't) The difference would only have to be close enough to not look out of place, rather than making a patch which will likely be different than the rest of the field.
