I got a kick out of item (b) and the 'because then “it will get you again.” '

The hybrids you describe match precisely with my experience with the -561 computer used in early LH2.4 Volvos. Though I'm surprised by learning new, previously impossible sounding truths most every day, I would have told someone they were crazy if they claimed Bosch drove their external fuel pump relay directly from a device on that hybrid. But its true (as of course you know) and remains true on the newer reliable versions. At least I can see that end of the hybrid circuit is completely revamped.

But you have the answer to a new, completely impossible sounding mystery: How does the marketplace for repair or replacement ECUs for cars out of production better than 10 years now afford the aftermarket redesign of such a specific chunk of circuitry? I might have believed there's business for a one-person outfit collecting good parts and doing rebuilds, but actually designing and sourcing an improved hybrid microcircuit? Pheew! Hope the best for you!