Community guidelines in a readme would be a good start. Also, educating those opening new git issues since I often see entitled and vitriolic demands from non-devs who do not understand what FOSS is (although I understand that this isn't the only bully archetype).

Maybe some inspiration from how OpenBSD handles users requesting features.
"No one deserves anything from us. /../ The developers in this project do the best they can"
or
"If you expected any of us to reply as if we are contractors or your employees, you came to the wrong place."

Probably some sort of mix, like federated or crowd-sourcing, but either simply means more maintainers/supervisors.

I think the article was pretty clear that (1) companies that use open source projects to make money should be contributing financially to them, and (2) users and contributors need to stop feeling entitled to maintainers' unpaid labor and time. Mostly 2 because it's a security risk AND a shitty way to treat people who are making something free for you.