They get soft and squishy during damp cold stratification. The Post Office would mash them up on their way to you and they would all be dead.
That said, some that have just had cold without the damp can take off right away after arrival. I just tried some as I am in a hurry. All my bonus seeds from that vendor germinated within a couple days!
The ones I am interested in though have done nothing.
As I have discussed with others it seems to be entirely cross dependent. Not all crosses will act the same way at all, despite the generic dogma.
My advice - split your seeds. Put half to cold damp stratification and test the other half right away. Then you cover all eventualities.
