I really love ZFS Native encryption, but this is the big problem with it. I use ZFS Raw Sends to store my backups incrementally in a cloud I trust, but not enough to have raw access to my files. ZFS has great attributes there, theoretically - I can send delta updates of my filesystems, and the receiver never has they keys to decrypt them.
I've used this in practice for many years (2020), and aside from encountering exactly this issue (though thankfully I did have a bookmark already in place), it's worked great. I've tested restores from these snapshots fairly regularly (~ quarterly), and only once had an issue related to a migration - I moved the source from one disk to another. This can have some negative effects on encryptionroots, which I was able to solve... But I really, really wish that ZFS tooling had better answers to it, such as being able to explicitly create and break these associations.
I've used this in practice for many years (2020), and aside from encountering exactly this issue (though thankfully I did have a bookmark already in place), it's worked great. I've tested restores from these snapshots fairly regularly (~ quarterly), and only once had an issue related to a migration - I moved the source from one disk to another. This can have some negative effects on encryptionroots, which I was able to solve... But I really, really wish that ZFS tooling had better answers to it, such as being able to explicitly create and break these associations.