I have no underlying theory about how save-points work. There's a part of me that thinks we trigger a save-point when we open the fridge, which is why we do it so often, pointlessly and randomly.
My
actual reading is that it's much harder than the average denomination believes, but is also more bless-ed than we seem to realize too. We're not ready to realize the scope of the forgiveness, though we might be made aware after we're transformed (as I said, there's either no Free Will in Heaven or else the revelation of Heaven effects some significant change in our desire to Sin). Or maybe there's cyclical Sin in Heaven, and some of use will choose Sin again. Who knows.
The adulteress (or lady merely accused of adultery, this part is actually unclear) wasn't forgiven by Jesus until right after she was about to be stoned*. The thieves on the cross got a last minute reprieve as well.
Death bed forgiveness doesn't work entirely with our intuitions about Justice, I will grant. A few people turn away from Christianity because the version of it that they were taught doesn't jive with their intuitions. I'd have to say that its insufficient morality is what started me on my questioning, though obviously my thirst for science also bumped up against the fact that I was raised by literalists.