Behavior outside a community should very little consequences inside of it. Of course there are some extreme cases where this might be a problem however those cases are extremely rare and should not generally be used for the basis of creating a Code of conduct or rule set

The wider political climate in world today is making have to be that simple.

While the article talks about more extreme cases like actual physical sexual assault, today far far far too many communities are using simple political disagreement and criticism and framing that as "harassment" using that "harassment" as method to remove any political dissenters from their ranks

I have seen it attempted (some times with great success) in several open source projects.

Personally I dislike the very concept of Codes of Conduct and I generally oppose most of the terms in many of the more modern Code of Conduct being pushed forward, likely as a result of my very libertarian political views. That said Codes of Conducts (should a community or project adopt them) should only be enforced based on actions WITH IN that community and/or toward people that are IN THAT community.

Not generalized actions of people taken in other communities with a different set of conventions and rules.

Code of Conduct should be seen as a contract of Behavior that all people agree to when voluntary associating with the community to treat all other MEMBERS of that community based on that code of conduct, it should not apply to conduct when interacting with people not a part of that community and thus never agreed to the code of conduct.