Steve Fredericks's Hatch Question/Help?

I will be making my hatch shortly. My intention has always been to use Steve Frederick's hatch seal system.
Looking at my galley/hatch it looks like I will have to put my 1/8" spacer and 1/2" seal plywood in the area outlined in red (see pic below). That seems like a lot of extra weight seeing how my Galley bulkhead is 57" and the counter top plus a few inches is 33"
Am I correct in thinking that is where those should go?
Any thoughts/suggestions or alternatives?





Looking at my galley/hatch it looks like I will have to put my 1/8" spacer and 1/2" seal plywood in the area outlined in red (see pic below). That seems like a lot of extra weight seeing how my Galley bulkhead is 57" and the counter top plus a few inches is 33"
Am I correct in thinking that is where those should go?
Any thoughts/suggestions or alternatives?