Thanks for your post. I confirm that calibration definitely operates as posted by the OP, it just isn’t calibrating correctly. I justed tested that it operates by following the steps but putting the levers in extremely random positions - this caused the throttle store these extreme positions. So it definitely functions, just not properly when I try to calibrate with the levers all at the exact same position.
So, my workaround for now? I ran the calibration with the middle lever slightly higher (0.5cm) than the right lever. The result after calibration is that they’re now more or less aligned. Oh my.