Its great that you were able to save the customer a lot of money by repurposing the used bracket. You were hit by a hurricane and still finished the conversion in 5 days? Amazing!
There are 26, 1/2 inch bolts holding the platform on bolted through the transom in a much wider base covering nearly the entire transom which is the most structural part of the boat. If the boat were to suffer an impact from the rear, it would be no different than before and if something were to hit it that hard it would be a disaster either way. quite frankly the outdrive hanging of the back is more fragile than the boat. if an impact to one or both of the drives were to happen most likely the gimbal would break and the u joint bellows compromised and then water would be coming in the boat from there