Yes. I agree with most of this. Though comparing ZBD to Primal is a bit different as ZBD existed prior to nostr and integrated in ways that made sense, doubly moreso in hindsight. Primal on the other hand is VC backed nostr from the get go, but attempting to use caching for scaling purposes in a way that breaks the experience. The similarities between ZBD and Primal can be summarized as both operating as a centralized silo.

As to Damus, Ive never used it but i get the impression that feature additions may have stopped or at least slowed considerably with notedeck under development. One thing I hope for Damus is that which I'd still like to see in Amethyst... robust list support. Though perhaps im overestimating the benefits of crowd driven organization and structure.