> My impressions had been that it largely mirrors the EV market: A few early PHEV models (such as the BMW i3) had poor battery management leading to unreliable battery packs.

BMW i3 owner here. The i3 never had such issues and has been praised for its overall great engineering (see https://www.youtube.com/watch?v=JjPIuLz5VFI and https://evclinic.eu/2024/11/03/which-used-ev-to-buy-a-beginn...). It is also not a PHEV but an EV that had an option for a range extender.