Sorry that I can't comment much on the whole mesh part but as a side note you might want to look into setting up pihole in your home network (no raspberry pi re

Sorry that I can't comment much on the whole mesh part but as a side note you might want to look into setting up pihole in your home network (no raspberry pi required). On your main router, deny all outgoing DNS requests and only allow those coming from the node you have pihole running. In that way you can track which of your devices is phoning back home and block accordingly