When your project faces this pressure how do you act to ensure that meaningful discussion happens and decisions are made that are the best for your actual users and contributors in the long run?

Make sure you know who your users are.

Keep in touch with them, reach out, do "community building". They will tell you things about your product/software/system you would otherwise never hear.

That way, you can also filter out issues from known troublestarters as noise, and, much like in Casablanca, it's a "round up the usual suspects" thing.

You could probably write a bot to filter them out, very similar to the ggautoblocker whose perl sources *are on GitHub, just, the other way 'round.