Blinky mode should be RPM limit not timing limit. Combine that with FDR limit and it is simple. FDR can also be different from track to track depending on size.
If speed is what differentiates the classes in each car category, do the simplest thing, limit final RPM to the wheels. Simple, done, top speed is limited. Leave mod to be open, decide on a top RPM for every other class and go racing.