The DM10 module box has a hole cut in the bottom to accept the rack mount, then two pieces of foam hold the box high enough in the case to accommodate the mount peg that pokes out the bottom.
The cases are awesome! They each have two casters and molded in handles on the opposite end, so they can be pulled along like a dolly. But one thing I noticed when going through tight spots, while the case is upright, it easily travels perfectly sideways! If I can fit through, the case will follow, no problem, no hassle!
I still plan to revisit the cases a little. That same guitarist has found a whole bunch of flight-case foam, so I may make them more like guitar cases for my drums. These cases also allow for adaptable depth, so when I add another kit, I'll be able to add another partition to each case to hold the added pads and cymbals.
My rack folds up nicely with the cable snake nicely strapped in place. When I get a second kit for expansion, I'll beef up this rack with the rack that comes with the new kit.
A King Size Flat sheet covers my drums in the studio when not in use