I think time based is the way to go, with an exponential curve, such that one can only post 5 comments reasonably per day.
The first comment in a given day has no wait. The second requires waiting 10 minutes. The 3rd requires an hour. The 4th requires 3 hours, and the 5th another 12 hours or so.
Obviously: No edits (or let the edit count as the comment).
Lots of variables to play with. The nice thing about time is that it is egalitarian. Richer people don't get more access.
> If you have to wait a minute to be allowed to post, can you still be bothered?
At work, I often log out of HN. The need to log back in often does act as a deterrent. I also occasionally use LeechBlock, with a 60s delay. That too acts as a deterrent.
> I also occasionally use LeechBlock, with a 60s delay.
Interesting. I've tried blocking things via hosts file to add that kind of friction, but it's too easy and often I'm waiting on something that takes longer than the time it takes me to 'fix' the hosts file.
> At work, I often log out of HN.
This works for me for posting but doesn't help so much with the FOMO of new threads. If I had to be logged in to view I imagine I'd read far fewer threads.