Hey Chimone, do you have any trouble with air flow to your burners with that setup?
My single-tier WIP is built from 3" angle steel - massive overkill, but I had a bunch of it available, so figured 'why not?' One drawback that I hadn't considered was that having the top squares roughly the same outer dimensions as the other Brutus clones but 3" wide means that the bottom ring of a keggle completely seals the hole - no gaps on the corners at all.
Without the ability to draw air from the top, the burners don't behave well. Even lowering the burners quite a bit below the frame, they only burn normally for a few minutes, then the individual blue flames vanish and are replaced by a vague blue-orange cloud of flame. This plasma ball floats around silently in the gap under the keggle for a couple minutes, looking like a terrible Evil Space Overlord special effect from the original Star Trek. Eventually, it gets bored and wanders over to the burner intake to try out its Space Shuttle booster rocket impression. Interesting as that is, I'm getting ready to make some changes to the design, though I haven't decided whether to just cut the hole wider or to add some 1/4" stainless plates to the top, with gaps between them.
I noticed in your stand pic, and some other close-ups from your gallery, that there's very little space in the corners once you added the rings to hold the kegs. Have you noticed any similar problems with draw at certain burner heights, or with a bit of wind?