1. If you want to block/unblock a single interface you have to specify it with a number:
And here comes a systemd unit which enables an USB Wifi dongle only:
rfkill unblock 1
And here comes a systemd unit which enables an USB Wifi dongle only:
/etc/systemd/system/rfkill-unblock-wifi.service
[Unit]
Description=RFKill-Unblock WiFi Devices
After=sys-subsystem-net-devices-wlan1.device
BindsTo=sys-subsystem-net-devices-wlan1.device
[Service]
Type=oneshot
ExecStart=/usr/sbin/rfkill unblock 1
ExecStop=
RemainAfterExit=no
[Install]
WantedBy=multi-user.target