I was also looking for OpenVPN for Arrakis, but there are few replacements, you can install OpenVPN for Debian (or which Linux do you run, but configuration is little bit tough).
Easier replacement is OpenVPN-Access server. It has just 2 connected devices in free version, but setup is user friendly and after installation it's possible to access settings in webgui (OVPN-AS, not OMV).
Which maker/mainboard do you have?
Most systems use the kes you've mentioned, but there are lists of theses keys around internet, like this one.
The same happened to me with "fastboot" enabled and SSD, the time to enter BIOS was too short. Solution was to unplug HDD, then computer was stucked on boot and it was possible to enter BIOS again.
Or if you have UEFI, you can boot from running linux direstly to EUFI with following command:
systemctl reboot --firmware-setup