The 2 Red Wires supply Power to the Starter Relay and to the Zeeltronic CDI.
There is one extra Red Wire required because now, the DC Zeel CDI needs DC Power directly from the Battery whereas the Stock AC CDI got AC Power from the Magneto Generator Charging Coil (Brown/White Wire from Flywheel Cover). So the Original Factory E-Box only comes with one Red Wire just for the Start Button to the Starter Relay.
Already have one Red Power Wire with a Split and a 10 Amp Fuse going to the Starter Relay (to energize the Starter) and to the Regulator/Rectifier (to charge the Battery). Connect one Zeel Red Wire to this existing Red Fused Wire.
For the other Zeel Red Wire, you need to supply/build/make-up another Red Wire with a 3 Amp Fuse and connect to the Red Battery Cable at the "Hot" Relay Post fed by the Red Battery Cable. This new Red Wire will provide constant DC Power from the Battery to the Zeel CDI.
So that's the missing piece of the Puzzle...