I have downloaded the slow stick plans, but have not found a build video, not sure how to set the dihedral or how the two halves of the main wing are joined?
The real slow stick has a center section that has beveled edge flanges you glue or tape together to set the angle and bent wire reinforcements for leading and trailing edge held on with a tape covering. Flexes mightily in large G manuevers and sometimes has more diehederal when it lands than when it took off.
I built a 1/2 scale version using all maker foam for the wing cradles and used a block of balsa for the motor mount. I bet a savvy builder could conjure up a full size slow stick using few to no printed parts. I'd do it myself, but my buddy has a printer and my stick is already hanging right above me waiting for Spring. Might be one for the FF challenge thread...
mounts could be made from a block of wood shaped to fit and drilled for the attachment. It would be ugly and heavier and time consuming. How we did it back in the last century before electric lights and color TV.