This is excellent. We are going to look into incorporating some (or all) of this into the core product. Nice work @nprofile1q...!
One reminder to all the Nostr devs out there: let's not centralize around Primal's caching infrastructure. Our stack is open source. Anyone can and should stand up their own instances.
Yes, our signer is built on the standard NIP-46 spec. We follow the spec precisely, there is nothing proprietary in our implementation.
You don't need to trust Primal with your nsec; our entire stack is open, so you can see precisely how we handling it. The idea behind building a signer is precisely to minimize the need for our users to paste their nsec into any new nostr app they wish to try.
Thanks for reporting and apologies for the outage. It seems to affect a small subset of our users but we were just able to reproduce it and are working on a fix. Aiming to deploy it first thing tomorrow.