Vince - I agree 100%. I use the plastic mounts in ALL my planes.
BUT, although your suggestion is an excellent one, it should go directrly to John.
Then, I will work with him to evalute it.
If it is feasable, I create a drawing of the proposed change and we send it to China for evaluation.
The only drawback to this type of system is the placement of the engine. In many cases, people will want to use a 4-stroke and due to it's somewhat higher weight but smaller tank requirement, the builder may want to push it back a bit, 1/2 to 1 inch. With a fixed location structural firewall, this does not work out well