And you are ignoring the fact that it may very well not be possible to test outside the Microsoft network. You know there is no way to access the reserved space of an Xbox application. That is security so that games files and game saves cannot be tampered with, making it a competitive environment. Developers themselves cannot test their addons on Xbox, they have to run on PC in DevMode and use the “simulate Xbox” menu option to test.
So, in the Xbox test labs, there are Xboxes that they can load into the reserved space. But is that because the hardware is wired into a network drive instead of a hard drive. If that is the case, the “hard drive” of the Xbox can’t be moved out of the Microsoft network, since it IS a network drive.
We don’t know. I do know they will work out the issue. I hate to say it, but if you want an environment where not only the developers but Asobo and Microsoft can easily test addons, then you probably have to go PC. I’m not saying that to be rude. But XBox is so locked down to ensure competitiveness between players, it makes some of what you insist good engineers do impossible. If you can’t live with that acceptance of risk that some Xbox products may have delays, then pc really is your only option