Pic mildly related; most recent shot I got.
Rebuilt the motor mount with 7075 alu and marine ply, and raised it above the transom. Started at 5 inches, and kept trimming it down after test runs. 3 inches seems perfect.
The anti-ventilation plate is now about 1" above the bottom of the hull in regular running mode. Can still get up on plane and go flat out without issue (it's actually faster than stock due to less drag), and in shallow water mode, the prop is 100% protected, being above the hull. Have no problems running in less than a foot of water, even fully loaded with 400lbs... can get to some really secluded areas.