I really like the damper feet of jorge_rui (https://www.thingiverse.com/thing:3316671). They do their job very well. But sometimes you have to move the printer and then you have to adjust the feet again.
Therefore I combined the feet of jorge_rui with the cable clip of Holspeed (https://www.thingiverse.com/thing:2960375). Now you can just clip the feet in the side of a 4040 profile and it will stay in place when you move the printer. You don't need any tools or remove anything.
For a small printer like the Ender-3 I used 4 feet (each corner one). For a larger printer with higher weight you could use more, i.e. one extra in the middle of each profile.
I designed one version with a special region for additional rubber pads and one without.
And there is one version which should be universal for 4040 profiles and one especially for the Ender-3, where you can leave the original rubber pads on the printer (see photos for details).
Choose the version you like and print one A-part and one B-part for one foot, i.e. "damper feet 4040 - A - rubber.stl" + "damper feet 4040 - B - Ender rubber.stl".
Everything fits perfect, but I am not in charged if you damage something. :)
100%, perhaps you can use less