In the ST TNG episode, Transfigurations (S3 E25), “John Doe” is discovered inside an escape pod and over the course of the episode, is transfigured into his species’ next evolutionary state, which obviously comes with quite a few perks.
Did Starfleet ever encounter “energy being John Doe” again? Or was his exit from the Enterprise D the only time they would ever encounter him?
Asking in context to Canon timeline. Novelizations/web info are acceptable.