Not to mention the sheer stupidity of having to lay boards face down on the floor to apply the foam.
It one of those ideas that might sound great if you're sat in a nice comfy swivel chair dreaming up new unnecessary products, to solve nonexistent problems.
When you're putting addy on the wall and you can see that there's a hollow in the blockwork, you just apply the adhesive a bit thicker (that bits not for you
@John j ) , that's never going to happen when you're head down squirting foam onto a board that's laid on the floor.