My current thinking is that the optimal shockmount setup varies depending on the situation. I have always wanted to do some controlled testing of that, exciting resonant frequencies and whatnot, but haven't gotten around to it.
There is a venue where there is a strong temptation to place your mics on a drink rail. Unfortunately some folks like to thunk their bottles when setting them down. A few folks think knocking a bottle on a table is a good alternative to applause. I think that is a good example of a low frequency source, where a loosely coupled shockmount, and light mics, are advantageous.
Other examples are stands placed on bouncy wooden floors, excited by subwoofers or stomping feet. You've got some guy who is going to play acoustic guitar and you setup a pair of mics a few feet in front of him. He starts playing, everything is great, then he starts stomping his foot like an absolute wild man. The stand is practically bouncing off the wooden floor. ("why didn't you tell me you were a stomper?"). That is a case where having some rubber tips on the feet of the stand may be helpful.
Whenever I have tried to mount full size bodies (cmc6's) on a bar in a single shockmount, it feels like too much mass for one shock mount, and too rigidly coupled.
I think another important factor is the loudness of the source and the amount of amplification required. A quiet source that requires 40 or 50 dB of gain will make the mics far more sensitive to vibration than a loud show. The same is true of wind noise, and the amount of required wind protection.
More massive suspended microphone assemblies can be made less prone to "handling noise" than a lighter ones. That's because a heavier suspended mass is less susceptible to the mechanical transmission of unwanted low frequency vibration than a lighter mass due to its inertia- it takes much less energy to start a lightweight mass moving when some unwanted vibration comes along and shakes it. Yet as a practical matter it is often much easier to suspend and rig small, lightweight microphones simply because they are, well, small and lightweight. Especially when they are perched atop a top-heavy light-stand. It's sort of a trade-off.
Likewise, big heavy luxury cars are easier to make smooth-riding and quiet than small lightweight economy cars for the same reason. Sports cars and race cars transmit more vibration and noise into the cockpit because they are less massive and their suspensions are intentionally not as compliant for increased road feel and improved stability control with reduced body roll.
Bottle clunking and metal rail pinging may actually transmit plenty of higher frequency noise as well, but that's easier for a flexible suspension to isolate than low frequency noise. One of the Rycote Lyre advantages is that the suspension is extremely complaint with an especially long range of motion in the axis perpendicular to the diaphragm, which is the axis in which the microphone is most susceptible to low frequency mechanical noise. They are available in different compliances to better 'tune' the suspension to various microphone masses, the less massive the suspended microphone, the more compliant the suspension needs to be to provide acceptable vibration isolation.
Acceptable suspension performance is a "good enough" thing. As long as it's good enough that handling noise isn't heard on the recording, other things become more important.
A higher source SPLs and resulting higher output signal level certainly helps suppress most sources of noise: mechanical 'handling noise', microphone self-noise, environmental room noise, crowd noise, wind-noise, the bar next door or stage in the next field, or whatever.