I stayed on induction for 5 months, although I did add foods like yogurt, nuts, berries etc. I just didn't go over 20 carbs a day. I was careful to eat lots of vegetables and fiber every day.

As I understand it, the concern about staying in induction too long is that one of the most common strategies to break a stall is to reduce carbs. But if you're already at induction levels then there's noplace to go. Other than that, I think there's no reason not to stay in induction as long as you want.