Ann: Company Update, page-77

But just because they know PL2 kinda worked and PL3 didn't work at all doesn't mean at all that :

1. They now know how to make it work
2. That it even works beyond cell level

I dont see why people think PL4 is so certain when really it's still a lot of guess work. Yes each iteration may bring you closer, but I only see PL4 as having incrementally increased chance of being a success. Still so many unknowns.

Their commentary doesn't seem to suggest an epiphany or "aha" moment. Maybe I missed it though? They still seem to be tinkering trying to find what works.