Boatman
I had the same setup on a 14 foot springbok not bad once you get up by a dog to get up same issue with weight the prop switch will not do much good in fact i steered clear as i was told by numerous shops it would stress the motor more than its worth its up to you whether you do this or not
now on to the part you dont wish to do I had some favourable results with a foil turning and on plane were enhanced plane not so much as turning
hope this helps
peter