I don't think it makes any sense for single-dev teams to develop multiplatform Nostr Clients.

The Client needs to be EXTREMELY simple/small to allow the dev to spend time integrating and testing in all OSs.

Maintaining multiplatform apps (either native or via NDK) takes time because both OSs and their libraries will update separately, with stuff that will break your app all the time and you will keep running after those fixes. It's a massive time sink.

Most multiplatform apps end up becoming too shallow to be useful because the dev is spending too much time trying to make things work everywhere.