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for reference: Chapter 6. Virtual Networking
I don’t see the point for that. Two network interfaces is a a feature. Not a bug. No clearnet leak bugs reported ever at this time.
As a general guide on how to make the case, see also:
For learning / experimenting OK but needless to say that in a production setup this could be a good way to introduce clearnet leaks.
I doubt there can be an easy answer in 15 minutes as this would require extensive Whonix firewall changes.
See also: