I'll have to disagree. Just to clarify - when there's an OpenVPN reconnect OpenVPN is able (as it should) to keep this hidden from the application layer (which just sees a connection through a TUN device). And if you look at the openvpn log messages (all this should be easier to monitor if you do it on a desktop computer) then you'll see that when this happens OpenVPN goes through the whole connection protocol again.

So, I believe that _technically_ it shouldn't be difficult for OpenVPN to disconnect the physical layer and re-connect through another physical layer (i.e. when you disconnect from one AP and reconnect via another): The re-connect phase should be the same. But that doesn't mean there's actual support for it.