As you know, there's going to be a range of desired bias currents, depending upon factors such as B+ on the tubes. If I were to rely on an automated circuit to perform bias sensing and adjustment duties, I'd want to be able to program it with the desired target bias current for the application. I'm thinking about DIP switches.
I think we had discussed that I have a 6L6 amp on the bench now that has a B+ of 530V. That exceeds the limits you'll find on the data sheets and the bias suggestions that you'll find in popular tables like Jim Jones' table:
So I'm going to tag along on this thread to see what kind of feedback you get.