The spinner is a discussion of danger , the mounts are more on the lines of performance and problems.
THe original release of the new mounts was on the new CMP 73" P40 .
If you look up FDL build of the 73" on RCU you will see that he used the kits rubber mounts and the movement and vibration forced him to take the engine out and rework the area with differant material .
I am not familar with your method as we cant see it in the pics but if you getting unusually vibration (higher then normal ) you may want to rethink your mounts .