I’m going to be carrying my spare Bosch pump just in case... big post-pump fuel filter on its way to me.

Checked all the engine bay electrical and vacuum connections around the fuel rails, distributor and so forth. No start/pump running continuously.

Switched the ignition a dozen times from OFF to ON, but not START. Each time the pump would run and not turn off. No start. Did the OFF-ON switch another dozen times and it started, seemingly a bit dry as it had to turn over many more times than usual before catching. 

What does repeatedly powering and de-powering the system do - give the ECU enough new map points?