Three things from Sly777's report (issue #1).
GENRE RADIOS SEE EVERY GENRE ON A TRACK
Subsonic's original genre field holds ONE value, so a track tagged "Hip-Hop; Funk" reported Hip-Hop and nothing else. A Funk radio could therefore only find tracks whose FIRST genre was literally Funk, which on a real library was one artist. The plugin now reads the OpenSubsonic genres array and matches on any of them, and a genre that is usually somebody's second tag can now rank high enough to get a radio at all.
Servers that do not implement the array are unaffected: the old field still works exactly as before, and there is a test holding that.
NEW MUSIC MEANS NEW TO YOU
It meant new to the LIBRARY, which on a library you have owned for years is not what the name promises. Tracks you have never played now come first. Ones you have played still follow rather than being dropped, so a thoroughly played library does not get an empty mix.
HOW MANY SONGS ONE ARTIST CAN CONTRIBUTE IS NOW A SETTING
"Most tracks from one artist", default 3, which is what it has always been so nothing changes unless you change it. Set it to 1 for a genre radio that spreads across as many artists as it can.
Filtering also got more careful: a genre on the denylist, or on almost the whole library, used to blank a track's genre completely. It now removes only that genre and keeps the useful ones.