This plugin is not used by QNAM, it is used by qml apps because QNAM/QtBearer is lacking. It is a generic connectivity helper adaptor, which should probably be in connectionagent anyway.

It is not QNAM controlling the connection, connman still controls it (QNAM connman backend still requests/get info over dbus). IMHO, it is better to use connman-qt to do the connection request, as we have  more info about the current state of the network, the connection and can skip duplicating the online check here, as we know when connman has finished it's own online check (when its state moved from "ready" to "online").