My experience is the same - mounts and matts don't survive international mail. I've received one which should have survived, as it was packed between two sheets of plywood. But somehow someone had managed to drive a nail through it! :o
I prefer to receive unmounted prints. Then at least the print has a fair chance of arriving undamaged.
Most of my prints are toned, but this is not so for lith prints. The colour variations in an untoned lith print are very different to what they are after toning, and sometimes I wish to retain the original colours. Any toning that is strong enough to make a difference in archivality is strong enough to change the tone, too.
I will use FB paper this time, though: Of the two "lithy" RC papers I have, one is way too glossy, and the other one is the same emulsion in the FB version.