On the other artists I tried, the new “Play Now” feature does what it’s supposed to - play songs only from the said artist in a Roon Radio sort of mode.
For some reason when I do this with Paul McCartney, it plays one McCartney track, and then there’s no next track suggested in the queue, i.e. the radio ends after 1 track.
@mike - I also tried playing a Lennon radio now and it timed out, gave an error and said it’s limiting the radio to the local library. I tried it twice more and the result was the same.