@SvenSommer Late but…
Running without root/sudo
Run the following command:
sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)
This grants the node binary cap_net_raw privileges, so it can start/stop BLE advertising.
Note: The above command requires setcap to be installed, it can be installed using the following:
sudo apt-get install libcap2-bin
This works on my Zero W with Debian Stretch