Would floor gliders like these (https://www.amazon.com/Furniture-Sliders-Gliders-Hardwood-Protectors/dp/B01N758Y4J) not work equally as well?
Possibly. However, they don't appear to mount via a mechanical connection or with adhesive. Since they're only held down by the weight of the object on top, they'll likely slide out from underneath the speaker's outriggers. The M3's don't weigh all that much. I could see the amazon units working better under something extremely heavy like a cabinet or full sized dresser.