I got to same conclusion, 'test ON', 'bad' OFF. I was only listening/testing with 'pink noise' at various Clipper level tho.
Wait, "BAD" off?! Off is NOT legacy mode. What I proposed it having both ON (which is equal to before adding them) and remove the settings.
Which I think is also what you said before:
HPF on brings less distortions on pink noise, ofc. And with that ON, (and ofc everyone will use HPF) i dont hear much difference with "test" ON or more distortions caused by bass. maybe even slighlty more bass. BAD has more bass too but also more/always distortions caused by bass.
Edit: I just read back through this thread and I see that I wasn't very clear - I meant that turning "BAD!" *off* would cause those things. But that seems to be the opposite of what you're saying. I'll run some tests, until now I only looked at the code and used reasoning to determine what would happen.
Edit 2: I did a quick test, and I heard what I expected: MUCH more highs IMD with BAD! turned off. It's not even a subtle difference. Am I missing something? Or did I misunderstand what you wrote? If not, can you send me audio + preset which shows this?
Edit 3: I found that I get the cleanest highs when the first frequency is set to 100 Hz instead of 80 (80, the default GUI-setting, is *just* slightly too low). For a not-insanely-steep filter the 2nd one would need to be set to at least 200 Hz, so I'll replace the values by 100/200 instead of reusing the settings in the GUI. The effect is pretty small, so no setting for this.
Recording, "BAD!" on vs off (both bass clipping thresholds at +6 dB):