Thread: How deep should a case be?
Why not this: https://pittsburghmodular.com/structure-344 ?
It's not 3 x 104...you lose 18 hp per row, but you wind up with MORE module space than a 3 x 104 in the end, plus built-in power (which eliminates that need to stick power access modules in with the "functional" ones) that is beyond ample. And you get a VERY useful utility tile-row in the bargain...and more than ample depth (101 mm max) to fit the most chunky modules. Not cheap, but you're getting what you pay for with one of these big wooden honkers.