Suggest you include brackets on the wall behind for cassettes in order to clear the main deck - you'll see something like this on Chris's original article.
I've like a few of Chris's ideas and certainly his solution it clearing the deck and transportation of rolling stock as a combine solution. I especially like his solution for automatically stopping engines running off the end of cassettes.
Front of deck could hinge down to improve access at rear, although you'd need a 2 hands catch to avoid disasters.
Hmm.. will have to give this some thought. May be appreciate this idea better when looking at a full size plan.
Biggest improvement to the system since originally published is the addition of an infill down the centre of the cassette leaving just 2 flangeways.
I've used these inserts on my Tredethy Wharf cassettes and appreciate their benefits.
You haven't mentioned layout height
I'm thinking of a similar rail height as Tredethy Wharf which is approximately 4'3". https://tredethywharf.blogspot.com/2010/05/all-this-for-just-three-inches.html