oil base stain, varnish or shellac is the one will be damage not the wood, why not put it in a glass or steel instead?, i have a 400W Logitech Z625, or the 400W Creative T6, despite this are heavy and powerful triple woofer bass box and super powerful satellites why it didn't leave a mark on a stained wood?
"Google ships the pad with the Max, but I had left the pad in the box, figuring it wasn’t that necessary."
Is there a reason you assumed the pad Google shipped with the speaker was not necessary? These rubber/silicone pads isolate the speaker and reduce low-end vibration transfer; this affects sounds quality. This is why everyone of the speakers reviewed have them, Google just made theirs for either speaker orientation. If you buy a pair of regular bookshelf speakers they will come with similar pads to stick on. They are typically referred to as "isolation pads" and have a very real affect on sound quality. You can find many articles and forums about this and people noting the increase in sold quality, especially if the speaker was on a hard surface. I just looked at your face off of the Sonos One, Homepod and Google Home Max and it is clear from the pictures that you do not have the pad under the Google Home Max. This will most likely negatively affect its sound quality especially since its on a hard desk where its going to have vibration transfer . Considering every other speaker had their pads because they are permanently attached, that is a disadvantage to the Max and may have affected its audio quality score.
This is still going on, let this nonsense story die already. There is nothing new about silicone and oil and wax finishes on wood. Lighter the load on silicon, the longer it takes to cause a mark. The heavier the load on the silicone, the faster the marks appear. After 2 weeks my google home mini left a very light mark. Also depends on which oil or wax you use, the time it takes the lighter devices to register a mark.