Updated with a fix to always use local cached files in Temp or RetroNET storage folder when there is no internet connection. This includes the NABU HomeBrew Channel list and existing downloaded programs.
So if you're going to use your NABU with no internet connection - simply run it with an internet connection first, run all the programs that you'll want to use and they'll be downloaded and cached. Downloaded programs are only downloaded again when they have been updated on remote.