Interesting read but I think I've moved past that. I was able to get a good enough picture of the coil discharges with my hillbilly inductive pickups to tell me sequencing looked good. I may be proven wrong on that, but chasing other demons now.

I ran it for a few minutes yesterday with the test cylinder (#4) being fired from the arduino. I may test more in this configuration tomorrow just to verify it was actually hitting (most of the time).