I keep my collection in the freezer with no ill effects.
When i want to germinate any seeds i will put them into the fridge for a couple of days to acclimatize.
I would never go from the freezer to say a 24 hour soak, would be definitely asking for trouble.
Yeah, if anything freezing will prolong viability. You just need to "thaw" them carefully.
Interesting... I hadn't considered the possibility of some kind of temperature 'shock factor'. Link to data?
My wife just thinks im batshit crazy. But im just a seed storage facility. Lol i have my own seed fridge. Not weird at all.