Hello new forum!
First of all, some OT appreciation to whoever set this up as a new haven for the lost souls of the former UM community! (That would be LePaul?)
THANK YOU!
Now on to the topic:
I made a design to decouple the feeder from the printer frame about two years back, when I got my UMO+. It is still hosted on YouMagine atm and can be found here:
Feeder Damper
It is an easy to install drop-in, you just need a zip-tie, or some wire to attach.
Overall, the TPU materials seem to break down a little over time, losing some degree of softness. However I did not feel the need to replace my print in two years. There was still some residual humming which I could get rid of by placing a small piece of foamed plastics (that mattress like stuff used for packaging electronics) under the bottom part touching the backplate.
At least with my UMO+ I found that most of the noise was produced by the stepping of the feeder resonating on the backplate acting as a "drumhead".
Rubber feet come in handy none the less
Regards,
Frederik