actual need for ballast resistor with electronic ignition?

I have three LA small block engines in street driven cars. All 1970 Darts with factory wiring.

All use Pertronix Flame Thrower coils. The one that has an MSD system and the one that uses a Mopar electronic ignition distributor with and FBO brand ECU have both had the Ballast Resistor bypassed as directed by MSD and FBO.

The last car has a Mopar electronic ignition with a Mopar orange ECU that has the ballast resistor functioning in the system. I realize that the purpose of the ballast resistor is to reduce the voltage to the coil between Run and Start (although I can never remember which mode has the reduced voltage). I understood that this was originally done in points ignition systems to extend the life of the points. Why is it needed with electronic ignition? What are the potential issues if the resistor is, in effect, bypassed?

In a Chrysler wiring diagram which is the Start and Run circuit (in the FSM they are labelled ignition 1 & ignition 2). One is a brown wire to the ballast resistor and one is Blue (and then blue with a tracer between the bulkhead connector and the welded connection which also feeds the blue alternator field wire and the blue voltage regulator wire). Which is which?

Thanks for your help!