Having a background in vibration control I have several comments
1. to reduce vibration you want a "shock absorber" that damps vibrations by turning kinetic energy into heat not a "spring" (capacitor) that stores energy and releases it later in time.
Drop Sorbothane on the floor and it bounces, it is not a good material for vibration control, proper companies like EAR and Soundcoat do make good vibration isolation materials
2. I designed a vibration isolation mount for my tripod and found the following:
a. mirror lockup (liveview) and a cable release was just as effective
b. mass damping by hanging a backpack from your tripod was very effective
c. the vibration isolation devise would let the camera sag a bit if it was pointed up or down and made composition a pain.
3. The most practical solution is a sturdy tripod with a hook, hang your backpack on it, use liveview and a cable release
4. I wish manufacturers would use some constrained layer damping materials around the mirror box it would help