Remote signing works. But remote decryption doesn't. There are too many things to decrypt in a single screen. Making a decrypt call for each message in a DM chat screen takes a long time.
We have been discussing this on https://github.com/nostr-protocol/nips/pull/746. Where the idea is to not have a decryption call on NIP-46 but a shared-key assembly call. Client can call it once and with a single key decrypt/encrypt all messages locally.