It's great on small tracks, I've bought mine specifically for that.
The only mods I've done prior to starting track days were tires and crash protection. Eventually, I'll probably be changing the suspension. Brakes and engine are both fine, I'll be keeping those stock.
Whether the Duke is the best among the listed bikes depends on what you want to do with it - if you want a pure track bike, better get something with clip-ons and fairings. However, if you intend to carry over the skills from the track to the street, and you ride a more upright bike, it's best to learn or something with similar ergos. IMO the Duke is the best small displacement naked bike for the track (compared to Z400, MT-03), most sporty, with a relatively stiff suspension, hard seat and active body positioning. It might not be the best small displacement bike for getting the fastest lap times. So the question is, are you planning to take part in races/cups or train to become better on the street?
2019 390 Duke