Somewhat related. You might find interesting:
On more information what Whonix, the gateway does, see these pages:
- Whonix ™ Networking Implementation Documentation
- Design - Whonix
- Anonymity Operating System Comparison - Whonix ™ vs Tails vs Tor Browser Bundle
- Whonix · GitHub
Yes, Whonix-Gateway would be a good platform to create an alternative VPNBOX or similar, but don’t hold your breath for it.