When I'm stuck in traffic I could force it to stay in EV mode with the switch. I would have to come to a stop because you can only enable EV mode when stopped. Also, when you are in traffic your engine is likely already warmed up, and with a light foot you can keep it in ev mode without the switch fairly easily. The switch is more useful when you're doing a cold start and don't want the ICE on. Thinking ahead, if I added additional capacity to the pack via another pack in parallel (or make them switched), I could run much farther on EV mode and plug into a charger to make a PHEV.
When the engine kicks back in it does not stay at a constant rpm. Once it is on, it is the main form of propulsion in addition to powering the motor/generator to charge the pack back up.
I just programmed in some handy x-gauge features on the
scangauge so I can monitor pack voltage and current draw/regen amps. This should prove very interesting on the trip to work tomorrow.