
My thought was to TB2 a canvas strip to the underside of the floor before the black glop, and fold it up, around, and lay it on the top of the floor, then after the wall is GG'ed down, TB2 the wall and strip of canvas and give it a right angle to pull around so that the force applied would be a slipping/shearing force instead of just pulling the canvas off the top of the floor.
The left side of the (bad) drawing is what I propose. Due to the absolutely horrendous selection of 2x4x10's at our local blue box store, I bought 2x6's to go where the drawings say "2x4"...so that is a bigger ledge than a 2x4 would make. I'd cut the floor two inches in, where the foam rests on the 2x6, with the floor (3/4 OSB) tight against it on the inside. That edge of OSB is what's to have a loose flap which will be glued to the inside surface of the wall. Bottom part of the reinforcing canvas strip will be glued and pinched between the flat-laying 2x6 and the floor, and the floor still has 3 1/2" of board to lay on, same as around the rest of the perimeter....
Thoughts?

(Bad) drawing is on scale of 1 square = 1 inch.