Spiral pins are what they are, they work well, they are a pain to remove. Much better than them removing themselves. Because this would only happen while blowing snow on the coldest day in January, and it would happen while turning around at the furthest point away from your garage. I have no experience in this but I did have a front axle break while blowing snow in the midst of a road while turning around.
Same thing for a grade 8 bolt or grade 2, or whatever bolt you'd have. it would break at the other end of a Iowa field while plowing. Again this has not happened to me, if it did I would get the pleasure of a Deere pulling me back to my truck.
Patience, persistence, and maybe a little curing are the best methods to get these spiral pins out. using the previously mentioned tips help a bunch too.