I have a carbon pushrod going to the splitter in my Alliance and have had no problems either with vibration of the rod or fatigue of the connectors in the 2 1/2 years it has been in there. This must be a run of a good 2 1/2 - 3 feet and I was using M3 connectors at either end. Up to you but you may want to try it without any support first and once you have had the engine running you will be able to see how it is responding. If there are no resonances set up at any rpm I wouldn't bother fitting anything. This is the simplest and lightest way to fit the pushrod! and if there is some vibration you can always fit a support afterwards.

The pull-pull system sounds good too, I have seen them done and they are very precise and light, although I would still probably use a carbon rod in my next plane simply because I am familiar with that set-up.

James