According to the "Slidecage" Online Slide, Thomas Beecham was in Kromagg Prime's human military, and was stationed on Earth 25 (a jungle world). Now, as we know from the episode, Thomas deserted the military and wandered for a while before deciding to return home, which landed him in the Slidecage (approximately ten years ago, since we see that it was just a month into his stay that he entered the walls, and he told Maggie he that had entered the walls ten years ago).
Now, what does this mean? Well, to be stationed on Earth 25, Thomas had to still be in the military. That makes it more than 10 years ago that he was on Earth 25. Calling that earth by that name insinuates the Kromagg numbering system (e.g. Earth 113)...and according to the "Common Ground" Online Slide, the Maggs are now conquering earths in the 150s of their system. So, it's beginning to look more and more like the Kromagg war wasn't just confined to the homeworld, and the Kromaggs have been possibly conquering other dimensions for quite some time (which finally sheds light to how the Maggs could have so many earths under their belt based on the "Common Ground" Online Slide's time schedule). Why else would the human military be sent out to other dimensions and the numbering system be the same? It makes sense if the Kromagg history from the "Genesis" Online Slide is to be believed...it says there that the Maggs smuggled out a sliding device at the same time they were exiled originally. What if they started using that tech to conquer other worlds and the Kromagg Prime humans found out. Then they may feel an obligation to help stop what they unleashed. At least at first...
This could be the reason the KP humans decided on the cloak. Much like the Nazis did...the Kromaggs' remaining forces (which would still amount to one-third the population of our Eastern Hemipshere if not more) would be out for blood. It's hard to stop something like that...especially if you're not expecting it or prepared for it. You see, the humans of Kromagg Prime would be cocky thinking they could easily take them out again with the weapon. Why do you think one third of the Kromaggs weren't killed the first time? Natural immunity? The weapon's no good...the Kromaggs laugh and start slaughtering the humans. So, the humans of the homeworld start hearing of these losses and close off the homeworld before the Maggs can get back. They choose to sacrifice their own people and hide because they can't see a way to beat the Magg menace before it's too late. They needed to buy time. Why else would the humans in the Slidecage be so afraid of Kromaggs coming to the homeworld? If that weapon still worked...they wouldn't care. So, my new estimation is that Quinn's hunt for the weapon is a wild goose chase. It doesn't even work on the Maggs who are left!