We had other updates of "KC s2M log&Invoice" recently, but this one is really big news. The new feature is a custom reporting tool. You can do "picture" of past moments (and export the results as CSV): to get a list with members, that have certain level (and maybe also ccap) at some time period. Also can set "min active days" and "max active days" - the time "window", where members had the selected level (and maybe ccap too) within the time period you set. All this is explained as a diagram at plugin's page, please check. Because it sounds easy, but is difficult to track all that info...
I have already created everything what you can imagine, and several things, that you can't imagine too :-)