I have just bought a GP Cap 232 and am installing a Moki 1.8. I was wondering if there is a reason why I could not add an extra layer of ply to the firewall, and directly mount the engine to the firewall, with extended bolts going into the backing plate? I have seen this done on .60 size planes, and I can see it benefiting by dropping a few ounces of mount weight, but what might the cons be? Thank you, Mike.

Weight is the only issue there really... add wood and epoxy... shouldn't be too big of an issue though.