That's really great feedback -- I was the dev behind nReduce. I think that makes total sense that removing the hard deadline reduced everyone's motivations.

Joe and I tried to play with a lot of the timing, from first using the notion of 3 month batches, to opening it up for people to join every week (and doing a weekly join session to onboard people), to just opening it up completely.

We didn't see any immediate overall engagement drop after opening it up for people to join anytime and set their own checkin day, but we did notice once people received less than three comments per week on their checkin they dropped off within a few weeks.