Hi Evan,
The Radio algorithm appears to be slated for change and feedback from users as to how they would like to see the radio feature work is being welcomed.
One idea might be to have it select music from genre tags on an album or group of albums with a “temperature slider” that determined the breadth of parent/sibling/cousin genre tag inclusion.
Apart from broadening the algorithm within a genre, how would you like to see the radio feature working ?