Who says that if you do not wait 60 days, your snakes will crumple up and die? I have a clean, healthy, adult male here that I observed and kept in quarantine for 30 days in my own home, with no negative effects observed. Someone could QT their snake for a few months without getting a proper fecel done on it, and it could have internals. But oh, they quarantined it and it is still alive, so it must be ok?
Again. What diseases would not have manifested themselves yet, but would have if I had waited another 4 weeks.
You have sick snakes in your collection (one or more have died) how do you know that the act of breeding won't set off some delayed infection in this animal that came out of QT too soon? Again what you do is your choice...but potential buyers will judge you by it.