It's pretty obvious you know what you're doing. Maybe take along an extra distributor to get you home in case it fails again. Not a fix, but would save you from your health issues maybe.
Run a straight 12 v power wire to it , see if the issue changes . Check for tight battery terminals and good clean grounds
I have had issues with the pickup causing modules to fail. It's been some time since I worked on an HEI but as I recall the resistance in the pickup was high causing the problem. An older professional edition Motors manual has the procedure for testing the pickup.