MotoBridge/GIN was a huge waste of taxpayer money if the purpose was as reported, to provide vital interoperability during major disasters. Anyone who has a basic understanding of critical communications knows civilian networks (both circuit switched and IP) become overloaded and subject to being offline. And were just another customer to "the phone company"
The best solutions are the simplest ones: common frequencies and field programmable VHF radios, ask any ham, or any woodland firefighter. During the wildfires in California, the expensive proprietary 800MHz trunking systems were ineffective. What did work for all the mutual aid agencies was using common VHF channels and portable repeaters. Caches of field programmable VHF radios allowed for on site programming and cloning, so everyone was on the same channels.
No dependence on Internet, or commercial networks, nor trunking controllers to coordinate response. The cost of such radios is a fraction of what these expensive and complex seems are, and prove themselves time and time again during real disasters. Having drills is great to identity resources, but in my opinion, money and time is wasted fancying vendors who want to push complex solutions.
It reminds me of the commercial a few years ago with a cat stuck in a tree, and all these first responders, command vehicles and people are standing around pondering what to do next when someone says simply "get a ladder!"