Well my engine even being balanced to less than a half gram on all rotating parts shakes A LOT...
But I do have a 107 LSA cam with lots of over lap...
You can see it go tight against the mount when I stall it up a bit. I'm not sure where the movement comes from as I have frame ties and a 12 point cage. (And the one solid mount on drives side.)
Looks pretty dang solid to me... Shaking at idle I don't care about, anything with a decent cam isn't going to purr smooth like a kitten at idle including my engine. I'll be annoyed if I feel vibrations while driving down the road, that's the only vibration I'm concerned with.