I happen to be using Coracle via NIP-46 login right now, actually. I generally use Alby as my signer extension on my desktop, but I am testing out Amber's NIP-46 signing option for a review I am writing.

I also use Amber for all signing on my mobile Nostr clients, using NIP-55 whenever possible.

I don't log into any clients that require my nsec whatsoever.

I think that's about the best we can do at this point. If NIP-46 signing was just a bit more reliable, I would go to just using Amber, and not use a browser extension either.