The recommendation on my last type, and as far as I am aware on the current, was 1 division or unit per 5 kt crosswind component. My experience supports this. I don't believe there is any harm in putting what you need on at the start of roll, and you can forget it for a while because up to 80 kts or so, ailerons are ineffective. Meanwhile, you can confirm the crosswind by feeling what rudder you need to keep straight, and then decide if that amount of aileron is actually needed. How do you know how much aileron is needed to hold level unless you actually start to experience wing lift? I think the aim to to avoid that situation. It's vital to have that aileron on for you when the wheels lift, because that is when startling things begin to happen if it's not there. From what I've seen, it happens very quickly indeed. So you have to decide are you going to stop it happening in the first place, or deal with it when you suddenly end up with a rapid roll away from the wind as soon as the wheels lift, and IMO opinion, belatedly correct a situation you have allowed to develop? As always, there are many ways to skin a cat.