Engine mount Minn Kota trolling motors.

My first question is if anyone has used these type of trolling motors
and would they recommend them?? I'm thinking of using the RT80EM
mounted to a tiller attached to my Bank Dory.

2. Would there be a problem if I attached the unit upsidedown so as to
limit the amount of draft needed to get the motor in the water. The
manual says the cavitation plate needs to be 13" under the water for
the engine to work. I'm thinking of attaching it to a wooden
cavitation plate built into the tiller but attach it on the bottom of
the plate so as to lessen the draft required to get the props in the
water. The comapny sent me an email reply saying they only recommend
instalation as per the instructions. Anyone see a problem with what
I'm thinking of doing???????