Been playing with locked Android phones. My mom's old Metro PCS phone has no root options and a ton of preinstalled apps.
Figured out how to delete or disable apps. Doesn't work for everything but I was able to delete the default launcher and Chrome.
Might look for a non-root way of blocking Google servers.
@art you can try using a VPN app that actually points to the local phone, and blocking through the VPN?
@art nextdns.io lets you set custom DNS blocklists, redirects etc. Especially if Android 9 which makes setting global DNS much easier, if not there's apps they provide which achieve the same :)
Can you put it in developer mode? If so, adb is your friend.
@art NetGuard comes to mind, available at @fdroidorg : https://f-droid.org/packages/eu.faircode.netguard/
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko