This would take out a certain number of them, but there are hardcoded IP references (e.g., to their DNS servers), use of Google systems for things like NTP, and

This would take out a certain number of them, but there are hardcoded IP references (e.g., to their DNS servers), use of Google systems for things like NTP, and so on. These are findable and patchable, but you will still be building your own image to maintain as most of these are not exposed as knobs in the Android UI. And of course still no answer for SUPL. Going transiently without an internet connection is common, but going semi-permanently without one is not what these systems are designed to do well. Also, is this list of ~10 hostnames readily available somewhere?