You can just build a recent modemmanager (0.6 branch probably) with the patch and run its modem-manager before starting network-manager and you have restored your old configuration by just killing the new modem-manager.
You can just build a recent modemmanager (0.6 branch probably) with the patch and run its modem-manager before starting network-manager and you have restored your old configuration by just killing the new modem-manager.