It is in the spreadsheet! We set PMs by the number of interactions, which we defined as either tagging someone (with
@username) with a question/comment or quoting and directly respond to what was in the quote (as distinguished from quoting and talking about what was in the quote, but not following up with the person who said it). Different numbers of interactions required for different heart levels, and we increased the number of interactions required once the roster got down to like 7 people because otherwise everyone was going to have a PM with everyone
It was a lot of work and one of the things that we're planning to modify for the redux game, tbh