I do not understand what the problem is, as I understand there is no speed limiter, only rpm limiter, which as you write 200 rpm is app 20 km/t, so figure your rpm at the speed you need your limit at and set that rpm as max.
You will always be able to pedal faster, but motor leans out at limit. The easy way to find and set limit is using the bluetooth and a phone with golden motor app, as it reads out rpm as well as speed if set up correctly.