One of my favorite features is having all four of my guiderails available (to the left) My 2700 is on the bottom, with the 1900 and 1400 above, and the rail from the MFT is on top. Each slot has a stop appropriate to its length. Because of the bracket on the MFT rail, and to maximize storage, I added a lid that lifts up at the back left of the van to better access the rails.
The next slot is for my quiver of Stabila levels, 1/4" mdf template material, and a jig I use to support narrow scribes.
The two other slots are for long clamps and a set of Fastcap Third Hands. These two slots do not need the full depth of the plinth, so I made another storage hatch forward of them with a flush-mounted piano hinge. This also allows me to make sure that nothing gets stuck at the back of these slots.
To the far right I have a storage "trough." Most of the time it lets me tuck my SawHelper wings and other lumber out of the way. I also included this so that I could still slide 48" wide sheets into the van vertically. When I need to pick up plywood, the SawHelper wings and such move out of the way.
One of my other favorite features is the taller platform on the right side over the wheel well. It's wide enough to accommodate the MFT, two pairs of Fatmax sawhorses, and the SawHelper stand tucks into the MFT. I actually use to strap these things to the right side before, too, but they would always slide down the wheel well and become a mess. Now I have some extra cubbies for shrinkwrap, some jobsite speakers, a bag of straps/tiedowns, and the MFT fence.
I used a phenolic-coated formply for the plinth top, which has its pluses and minuses. The good thing is that it is super durable and easy to slide things around on. The downside is that it is super easy for things to slide around on

I made some removable 2" tall partitions with 5mm dominos glued in (tight setting), and then bored matching mortises in the top at the medium setting. These help keep things from moving around too much. I bored the top at a full 20mm depth so that sawdust couldn't accumulate in the holes.