Here is what I did on my
Irwin 40 works good has never fallen out and even though it looks close to the berth i almost never hit it with my feet
Basically used a couple of pieces of
wood and some
aluminum strips from Lowe's
hardware. I am glad I did storing that thing was a pain in the ass lol Mine has a
plywood bottom but i thing you could do the same if your cushion is separate just Velcro the cushion to the
plywood insert. Hope this gives you some ideas, let us know what you do in the end