I don't know about the iso mounts helping the air cleaner situation ----
I think while they prevent some vibration from going to the chassis,
the direct mount of the air cleaner to the carb allows all vibration to transmit to it, maybe more, because the engine is allowed to shake more than a solid mounted engine.
But the fact remains, the bigger the piston the more vibration produced as we know.
I like Deere's mounting system, as it allows the engine to rotate about the center line of the crankshaft rather than cubs idea where the vibration is like holding a Dandelion by the stem in a wind.
Poor description but I think most understand.
Just some of my thoughts, that's all.----