Dirtwheels did a feature on a CR5 powered 250R quad a long time ago. The builder said he rubber mounted everything in an effort to kill the vibes but to no avail.
Quad frames tend to resonate the vibrations, their frame has no way to dampen the vibes I mean.
A trike kills the vibes through the forks somewhat.
I'd still do it, you know it'll be fun and with some fatbars and bar slugs plus rubber mounted clamps you'll manage to ignore the vibes.
Brace the frame and make sure your motor mounts are strong!