I believe that one of the important insights of the Discourse team is to place a value on reading. It is good to have readers of the discussions in a community.
However, there is nothing to read unless others write in order to be read.
But incentivizing just writing can lead to lots of quantity without quality. Which results in losing readers.
Thinking this through, I would propose that Discourse surface to each community participant how much time others have spent reading their contributions to the community.
This is a quality signal that is independent of the quantity of their contributions (though of course there may be some correlations).