I too am a beta tester. I was installed and calibrated the day before yesterday (Tue), so yesterday was my first full day on it. (Hope I am not breaking any confidences here! I know that if I wasn't on beta I would be keen to know what was going on ...)
I haven't been monitoring voltage etc, just observing regular (probably daily on average; sometimes none, sometimes two) step-downs in reported charge. Typically from mid-high 20%s to 4%. This has happened pretty much since I was installed a month ago.
Yesterday I did have a step-down while on the beta. It was a typical Autumn day for me - charge to 100% overnight, a bit of solar top-up during the day (very little yesterday), then run down until the next nightly charge. The step-down happened at around 11.30pm, from 8% to 0%. So, a less consequential declared loss than before, but to a lower declared charge level. Close, but no cigar just yet.
One thing to note - I only had a "semi-calibration" on Tuesday - a charge up to 100% but not a discharge. So I wonder whether the floor of the reported charge was not being shown properly. Maybe if that was the case then I will not get a step-down tonight, if it has now reset itself. Today looks like it will be similar to yesterday - little solar coming in because of the rain - and I will try and burn through a bit more electricity to see what happens when the charge gets low.
As Kwaka says - fingers are very crossed!