Ooof - that was quick - and well spotted as it only went live about 20 mins ago!
You can now add the balance used to report playings and I'm presenting a graph of the balance probability range, as you've seen:
View attachment 24080
You can find this feature on the view balance report and the bottom part of the latest games logged on each scenario page. You can also log the balance, and edit previously added games with the balance but I haven't figured out a tidy way to show which games have been played with any balance on the usual tables.
I'm working with the professor (Indy, of course) on how we get players' ELO to interact with this range, as it does seem to have a slight impact, which is why you'll see the average elo information at the bottom of that page.