I made a nail down plate that I lay on a nail head (starting with the lowest nail), then have a top plate that lays on top of the shingle. I can wail with a sledge hammer and no damage to shingles.
However, I’d rather take the nails out.
The problem is you can’t bend arch shingles up like single ply 3-tap.
But when heated you can simply pull on the top ply and it will separate allowing both plys to bend freely. I figure if I separate the nearby top plys, I’ll be able to bend both plys up enough to remove the nails.
Any other suggestions?