This thing looks like it is built like a rock. I’m having fun with the SketchUp viewer on iPad for sure. My first suggestion is to remove the crossbeam on the front floor area so you can slide your drainage tub/container in and out easily. It should not affect the structural integrity of what you built.
Also, the double beams on the floor going front to back are going to make cleaning those areas very troublesome.
Lastly, I would design the cabinet so that it can be taken apart in sections. Each cage could stand alone or be put together with the middle piece shelves and fridge area in the original design. It would make the whole thing more versatile in the long term. It would also make moving this beast something less deadly
Really cool design here. Thanks for sharing with us