Sort of both.
For those not familiar, most Dumble style amps have a trimpot that can be used to adjust the balance of the PI.
I tried adjusting by ear and didn't hear much difference by playing a little, putting the guitar down, adjusting, and playing more.
I also tried adjusting with a looper in front and didn't hear much difference.
Then I stopped running guitar signal in and measured voltages, played again, and still not a ton of difference.
Finally I thought "well let's just run a sine wave in the input and activate everything and listen to what happens. And I'll also record a few seconds into logic and use a frequency analyser to see what's going on..."
I could see changes in voltage based on master volume settings AND at different frequencies.
I think I ended up using 880hz as the test and was able to get the PI voltages within the recommended 6v difference between the plates.
The play test confirmed it was where I wanted it. Big cleans with little to no sag from the output section.