Question FlexBOSS Screen kit

My EG4 FlexBOSS21/ GridBOSS system package included a "Screen Kit".  I have it connected and working, but for now it's just laying inside the FlexBOSS21 door looking for a home.  It seems to work fine.  I have not used it much, partly because it's sort of awkward to use just lying loose in there.

This is an indoor installation (garage), So I don't need it to be water tight.

I am considering cutting a hole in the FlexBOSS door and fitting it securely such that the electronics is inside with the screen itself out on the front surface. It would be sealed -- just because.

One of the reasons we installed this hybrid system is for resilience for weather, wild fire, earthquake, and other such disasters.  For example, we have endured weeks long events without utilities including power and even loss of cellular services.  Yep, it's rural southern Oregon.  So, the Screen kit might be useful. I haven't verified that the screen kit works entirely without Internet but I will test that soon. 

So, my questions:

• Comments on the Screen Kit as to usability when off grid due to utility outage and even when on grid?
• Opinions and pitfalls if mounted through the FlexBOSS  door?
• Source or part number for a surplus door.? Just in case this does not work out.  I would like do the project on a surplus door, keeping the original as a way to revert to normal.
• Is it better to direct connect to the dongle with my Android app and forgo the Screen kit? I do this occasionally for other uses such a bore scopes and other shop tools.  I'm not sure the app has all the features I might need.  Direct connect sort of a pain, actually.