I think this had been tried years ago...
Yep. Good memory, guy. Two cabinets, like this one, with room for 12 modules each. The curse of modulars has always been that the manufacturer tries "the Apple strategy" and uses proprietary modules and connections, so if they don't make all the modules YOU want, then their format becomes a deterrent. Korg tried it. SCI tried it. MXR tried it. Vesta tried it. And probably some others. And they were all consigned to the dustbin of history because of that limitation.