The bolts hold the motor in place. Resting on the transom affords no advantage. Few factory setup boats have the engine all the way down, unless they did no engineering trials before they sold the boat.
update: i raised the engine 2 bolt holes and that pretty much put the cav plate at the bottom of the drain hole. runs much better. needs less trim and jump on plane quicker. still maxing out at around 26 mph at 5500 rpms
