@selje Enphase info is here:

https://enphase.com/support/sunpower

They informed me that a replacement system would be $700, seemingly including installation. It'll be a little while before I can generate enthusiasm for spending that money, certainly...

Some new form of SunPower resurrecting the current hardware would be nice. I'd say that the chances of them making it work again without demanding more money are pretty small, though. Such is the world we live in - we only *think* we own that device...