The space under the Bed in our FR EVO 2360 TT was wide open and into the Pass through space. DW and I decided we did not like Items Such as Linen and things Sliding or falling into the Pass through space were all manner of things would be stored. So I decided to partition it off using 1/2 inch plywood 51 inches long and 19 inches high and 8ea 1 5/8th inch sheetrock screwsto hold the partition in place. it was a very easy Mod or fix that took about 15 minutes to do. you can reach inside of the pass through outside doors to fasten the partition to the Bed frame posts inside the Pass through space. See picture below.
You can still see the pass through space and anything in it, but the partition keeps linens and things from traveling into the pass through space. A very simple fix.