I agree with you wholeheartedly that the wood is a bad idea.
I wasn't concerned about the the rubber on your stands disintegrating, it sounds like the manufacturer cares about quality, and at $20 a pop I assume the pads are top quality
, but I still have this question... repeated here:
I wonder if the pad might compress too much in the center (especially since it appears to be heavily slotted) causing the edges (where the metal lips are under the pad) to contact the side of the car when used with the car's rubber jack point.
I have that problem if I use my jack under the rubber jack point of my car. The metal cup hits the side of the car because both the rubber on the jack and on the car compress under load. My jack has higher protrusions so it's more of a problem, but I wonder about the protruding lips on the AC jack stand.
If you've never tried it on an MB jack point, I'd be happy to accept a complimentary sample and write a review.