I think it will work, but it's a lot bigger and bulkier than it needs to be. The goal here is to plane the boat, not float it higher. When I began layout hunting, back in the '70's, it was quite common to see layouts for sale with a "planing board" included. Back then, the boats were all big heavy wood or wood-and-fiberglass jobs which were just too heavy to pick up and throw across the gunwales of the average tender. A planing board was basically a piece of plywood strapped across the front of the boat on an upward angle, acting like the upturned front end of a really wide water ski. On your boat, it would also extend under water to overlap the flat front face of your pit or box, unless the front of your box is already angled upward (it's not visible in the pictures because the foam is hiding it). Of course, you have to devise a way to attach the board to the boat and then attach a tow rope or bridle to the board. For my boat, I made my planing board out of fiberglass that fits the front shape of the boat and flares up and out. Works like a charm and stows away easily in the tender, taking up very little room. Back then, I had a 16' Starcraft tender with a 15 horse johnson on it. The 15 planed both boats, including the whole rig plus hunters. Nowadays I pull it with a 50hp Mercury, and unless the water's really choppy, I tow it wide open without problem. My layout is not as wide as yours though.