Cool, thanks! I tested it after reinstalling my internet cube from scratch. I ran it connected as root in ssh, but I guess should be run as admin with:
sudo bash deploy.sh
It created a DHCP server on my usb ethernet adapter. All devices connected to this eth1 interface go through my VPN at ARN. It works like a charm but after some testing it looks like it requires the hotspot_ynh wifi app.
Thus I wonder why not just adapting the hotspot_ynh app to provide an optional eth1 configuration.