I ride on public gravel roads and some paved roads between the gravel roads, but none are major highways. Not many people drive on them, and I turn on my headlights.
It's just to get from one area to another, no more than 5 minutes or so at the most. Until I get a ticket, I will continue. I don't go fast. I don't think my Ace has ever gone over 35 mph.
I normally run around 20 mph on roads. I see farm and timber equipment running these roads more than I do, without lights. I know it's legal for them, as long as they have the orange triangle.