I thought 0xchat and ameythst rotate keys with a 2nd layer, you're saying they use the same 2nd layer over and over ? (note: I'm asking, not saying I researched this)
Discussion
As far as I know, Amethyst DM uses NIP-17 and does not have forward secrecy. The default DM in 0xchat also uses NIP-17 and lacks forward secrecy. However, 0xchat has a "Secret chat" mode that can be manually enabled, where both parties exchange Alias Keys and then use NIP-17. This type of secret chat offers some level of forward secrecy.
nostr:note1lscq8kz2huwnzngtdfqs22r7wlrasjy7uavcq22gjzxu8zawknqsvjy29d
great explanation, thank you. If you want we can interview you, and put it on our website.. blasting it out