Just wanted to post a quick update to my last post. I picked up my ActiveE yesterday and so far so good. Today was a very hot day and I was able to charge without any GFCI faults on my public ChargePoint charger. That's the one that was giving me the GFCI faults on hot days, and today being well in the 90's would have definitely given me a fault if I hadn't had it in for service.
So hopefully BMW has figured this one out and will correct the problem the rest of the ActiveE fleet as they go in for service. More importantly, they make sure the i3 and i8 don't also have these GFCI faults.
As you might imagine, I'm very happy to be back to driving on sunshine! :)