I've known guys who have done it, but never tried it myself - so I really can't comment on it.
Given that people are unlikely to admit they've made a mistake, it's not likely anyone would say that it was a bad idea on their part.
My comment has to be my old favorite, that Mr. Honda generally knew what he was doing.
So I doubt if I'd try it myself, but that's just me. I just live with the "buzz".
I'm generally reluctant to try and second-guess Honda''s engineers........I think to do so would be incredibly arrogant on my part, as I'm not an automotive engineer. I usually restrict myself to things I actually know something about. I was a pretty good mechanic, but not a design engineer.
The fact that these bikes (450's) still run (and run well) on a design done in the early '60's is a testament to their knowledge and expertise.
Back in The Day, Honda used to send out R&D Teams to visit shops and talk to us mechanics - the level of knowledge these guys displayed was truly humbling to us.
Don't mean to sound pompous or belittling, but that's my opinion.
If I tried anything, I might try modifying those mounts with some sort of rubber bushings or something like that.