I incorporated a rev limiter to the Vampire knock controller a couple years ago.
The rev limiter can be used for top end or for staging, and can be enabled with either a 12v or a ground signal.
No wires are cut or intercepted. For EDIS with waste spark, you would need a three channel Vampire.
Features are individual cylinder knock retard, boost retard, nitrous retard, and an adjustable rev limiter.
The rev limiter operates by swallowing just enough energy from the coil to kill the spark.
For six cylinder operation, software fires three cylinders, skips two, then repeats. This rotates the misfiring cylinders, preventing plug fouling.
Video showing operation here:
https://www.youtube.com/watch?v=5NjYMpQwaQ8
In case of twin plugs, I have a "Dual Three Channel" version. The six control wires tap into the six coil negative signals. See connection diagram below:
