- it automatically switches networks, both to and from WiFi
- it does not disconnect when switching
- the 1.1.1.1 app does not make anything more spotty or unreliable; it’s just DNS. Openvpn yes, but this app clearly not.
As for the battery issue: could very well be true, I have no idea how to test it.
The difference between this app and an actual VPN are clear from using it.