Parallel ignition systems, anybody tried running one?

We ran the chrome box on the street with the correct ballast resistor with a blaster coil. I just had 2 resistors mounted and both an orange and chrome next to each other. Ended up just running the chrome and ultimately removed the orange. We didn't cook the coil but the car had 391 gears and some rpm a lot of the time!
1) Did the timing retard when switching to the Chrome box with more dwell?
2) I assume You just switched it at the track(or fave street venue) before racing, not on the fly?
3) Both boxes were spliced in parallel to the pickup coil?