Hey Jim,
Yes, the wasteboard slats and the T-tracs are screwed directly on top of the original wasteboard. And the T-tracs are laid down about 3/4" from the front edge of the frame to allow the T-screws to load from the front as well as the back…
The T-tracs are 3/8" high and the wasteboard is 3/4" high, so they are recessed below the edge of the wasteboard.
One other thing… I bought six 3" carriage bolts for my hold downs and ground two sides of the head to form the “T” and just a tad off the top and they make perfect T-screws.
Hope this helps.
Bill