Good news, in the latest update it looks like Bambu has fixed the save bug.
They have also added a toggle so it can be disabled without wiping the value.
Also in case anyone was wondering, it is most definitely possible to apply a skew while your printer is running. Be careful though. What I had in mind was micro-stepping skew value within the same print, so a calibration can be done with actual values being tested. I believe it will be possible to calibrate skew without any calculations at all. I have nothing against calculations, but my printer’s gantry will never be a perfect square so it doesn’t care about math.
Here’s an example:
5x5 grid of 4mmx4mm cubes printed on top of a thin raft. the first cube is printed with a skew of -0.5 deg, second is printed with a skew of -0.45 deg … and so on. The model will appear as a grid of perfect cubes, and gcode will be used to apply skew.
Then measure each cube. This model can be created with a script, so the skew range and grid size could be customized.