It is not possible because it is not possible to explicitly start/stop the connection with my plugin.
You may have a look at https://play.google.com/store/apps/deta ... m.bluexvpn
. This does basically the same, without root (!). The only drawbacks are: you must start/stop it manually and it sucks the battery empty very fast (at least when I tested it). The latter may be fixed by the app developer.