Quick question though, why would the green and white wires tied together at the negative side of the coil work the same as the violet rpm limiter wire to the distributor mag wire? I would rather do it the white to green wire way as to not splice into the distributor wire. Really curious what you saw to know that would work also.
The wiring diagram for points or ignition amplifier work that way. The white wire senses the coil primary signal for RPM. The green wire loads circuit, to disable spark when RPM exceeds limit.
Best check with MSD, phone number is at bottom of instructions. Hold them accountable. :)