Ah, now I understand your issue. I don't actually eat the skin on any of mine - I cook them with it on sometimes to keep the meat moist, then boil it to make stock, so getting every last pin feather out is not super important to me, although I do my best. I tried with a couple of birds to be super thorough, and it took maybe 20 minutes? So I changed my scalding a bit, and my plucking technique to make it faster.
Have you tried using a pinning knife? I think a dull table knife works just as well. Also, when I scald mine (145-150F), I do it until the pin feathers come out easily when I pull them. There's usually a couple in the tail that give me trouble but if I test on the wing, then all those come out fine. Also, check the angle you're pulling them out at - this can influence how/if pinfeathers are left. There may also be some areas of the bird you want to just cut them out (for instance I cut off the tail, so I don't bother to pluck the stubborn ones there). Also consider getting more grippy gloves and using them just for plucking (not parting the bird). They'd need to be washed in the washing machine when done, but those garden gloves that are fabric but sprayed or dipped in rubber to make them grippy but are still thin and easy to work with would probably make super fast work of plucking even the most stubborn feathers cause you could get a better grip. Kinda like the plucking fingers but on your hand.