OK, here’s a diorama accessory for aircraft or armor, or any other idea you can come up in 1/144 scale. How about N Gauge railroading?
The product is a set of 6 metal barriers with legs and connectors, so you could make a hexagonal pen, or put 6 of them against a wall with a 2X2 setup and the wall is the 4th side.
There was a time when I wished we had those barriers for the static display aircraft at my Guard unit’s air show. In spite of the “NO SMOKING” signs prominently displayed around the aircraft, there was one guy who lit one up. Right under the wing of an F-14. Next to the fuel tank. Well, it was a shady spot. I called him on the “no smoking” rule, and he was going to put his cigarette out in the nicely provided butt can. Except this can was actually for overflowed fuel from the wing tank, and if I hadn’t physically restrained him, he would have burned himself and the aircraft. And possibly me too.