To me the idea is more important than implementation details because those can be worked out in many different ways as you’ve noticed. If you know what is the goal then you can adjust if you see things not working out as intended.
The most basic approach would be to get positive/negative ratio and decide how much in the middle is still 0.
What’s important is that it’s possible if you don’t like any other instance. Maybe once Lemmy gets popular we’ll get commercial hosts offering to spin up a Lemmy instance the same way they offer WordPress.