Originally Posted by CliftonGK1

If I'm seeing it correctly, the Zertz insert is an elastomer damper inside the frame/fork/post/bars or whatever other part they've put them inside. Any vibration damping effects will be through very slight transferrence from the stiff frame material these elastomers are butted against, however the majority of the vibration will still be transmitted directly through the frame/fork material.

A motor mount is a totally different concept. It's actually separating the machine from the surface/frame and significantly reducing the vibration that can be transferred to that surface. If the Zertz elastomer material was used as an isolation mount rather than an insert, you'd see the same damping effect (like a shock absorber.) You'd also see significant power loss due to frame flex at these damping points.