Several things:
1) Sorry about the 'Cup AND I MEAN THAT!
Where the Hell are the Swiss gonna defend it? I prefer Kiwis to most humans---check the make of my car (Ron Butler's engineering went into it).
2) You are right about solid mounting---it does eliminate flex-stresses on exhaust systems, even wiring! BUT (as you also point out) it brings in problems of harmonics, high potential for fatigue---even from micro-vibrations (which the occupants
don't fee)l---so-o-o-o:
3) what I noticed a lot of race cars during in the 60"s and 70's (back when the public could view the cars up close in paddock areas and up on lifts) was---ALUMINUM! Repeat aluminum! Don't ask me how that works---it's just a tiny bIt softer. They used it on ALL flex-joints: suspension AND motor-mounts. It DOES eliminate any lean when it's used to replace suspension bushings---but I will leave it to more knowledgeable people---like Ron Butler about really using it everywhere. If you can borrow the boss's phone at work, call Ron at Butler Racing in VenturaCalifornia...(805) 649-6000. That call COULD actually be less expensive than your car!
G'luck.