[Bigbadvoodooguru]

So to follow up, I was looking for mounting solutions and found one that works quite well. Zero drilling into the car, both cupholders preserved.
I'll let the pictures do the talking.
















Things left to do: Mount the aforementioned magnet, which I now have, and mount a couple slanted rubber alignment pegs to the front underside of the armrest. When closed it will center the armrest over the opening, and remove any side-side play on the armrest. As it is now, there is barely any, but like any lever it will move side-side if you push on it. There is zero wobble or instability, or even a tendency for the armrest to move or pull out of the console despite not being hard-mounted to the vehicle. The alignment pegs on the cupholder insert + console box are pretty tight.