Decouple motor/bearing or both?

I'm contemplating a new plinth build in bamboo and has decided that I'd like to decouple the motor from the plinth. I'm thinking about mounting motor and bearing on some threaded rod so that I can adjust height of both easily. I'm also thinking about decoupling the bearing as well. Would this give me any additional benefit, or is decoupling the motor on it's own better? I'm toying around with the idea bracing the bearing to the base of the plinth just like Mike's PTP and Jolly's bearing design. I'm perplexed and really would like some help! grin