Info on FBO ecu unit

No need to reduce dwell until under ~ 3 k rpm to avoid coil overheat is why , and how they can eliminate ballast R So may do nothing till that area down ?

Regardless, the standard coils were all designed assuming some type of control on the current allowed through.
Until, HEI, most companies used a resistor of some sort. The ballast resistor having the advantage of slightly lower resistance when cooled by more air flowing through the engine bay.
HEI used solid state electronics to control the current. @KitCarlson may have posted the specifics at some point in the past.