[gwinsyth]

Depends on brand. I have one with 4 distinct controls for each heat source. But when I was changing my stove, this was something I looked for - I've used those that can set only one heat source at the time, and they are infuriating for me too.

As for knobs, I'm willing to bet that there are some induction stoves with knobs.

[morsch]

There are. Like you said, you just have to know that's a feature you want and look out for it.