actual need for ballast resistor with electronic ignition?

str12-340 said
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?

Ignition 1 is Run, and is blue or blue with trace. J2
J is used because I can be confused for a 1

Ignition 2 is for Start, and was brown, J3.
At some point in the early 1970s, the ignition connection to the coil was given brown insulation instead of blue. Regardless, it is the feed to the coil. When is engine starting J3 bypasses the ballast because system voltage is already low, and if anything starting requires more spark energy than running.

str12-340 said
Why is it needed with electronic ignition? What are the potential issues if the resistor is, in effect, bypassed?

Its still needed so the coil gets the right amount of electrical energy to saturate.
If the coil was designed to run at 14 V (more resistance in the primary winding) then it would not work so great during startup.
Additionally using the ballast resistor (rather than resistance wire bundled in the harness) provides a little more cooling, especially at higher speed. This also helps the coil.