I am using stock android with netguard. Does blocking network access to Google play services and services framework stop my phone from sending personal data to google? Or is there another hidden process that does this job?
Blocking method won’t be the recommended in the first place to stay away from google tracking.
Ideally using a vanilla -gapples OS/rom would be the best scenario.
But if you can’t for some reason or the other , i would try to disable them altogether (for ex through adb).
Though this method too can bring lot of instability in the system , and you have to test it out if there any crashes on your phone (Mine survived easily) .
The least preferred method would be blocking the goolag. Though it may cut off major components from internet but using a VPN-based firewall may lead to leakages ,like when phone boots or you forget to turn it on.
Also your phone may consume more battery as the playstore might not function properly. Also apps would lose the ability to show push notifications and may not even shift to other forms of push like persistent connection as they would still detect google play and try to communicate with.
New apps still could get identifiers regarding you by communicating with the play services.
Lastly , depending upon oem , there maybe chances that the oem allows some apps to byapss the VPN totally so rendering any blocking through netguard useless.
For example the “root” package of android bypasses the vpn rules , so any connection made by it cannot be blocked.
So personally i wouldn’t go with this setup , i would either remove goolag altogether or let it connect properly so that the device behaves properly.