My initial thought was to do this when a series (or cour) ends. If an average show goes through 3 LN volumes in 12 episodes that would average out to one volume per month. I think that is an achievable goal even for casual readers that are interested to participate. The con would be that this seasonal rhythm doesn’t exactly foster discussion and participation. So maybe something in the middle be feasible. Either a monthly post where the difference in the past month could be discussed, or series specific post after each arc or thematic break.

Another question would be which series would be chosen. Does everyone pick their own, or should there be a poll before a anime season starts. In regards to that I would think that as long as the community is so small it would be better to chose only one series via poll so that there is some potential for discussion and not everyone doing it for themself.

At the end of the season the results could be consolidated into a Megathread for future reference. Or maybe even an external Wiki. If I find a way to not doxx myself I could throw one up on my server.