I wonder if you've noticed I was running None ERS setting at the later half of almost every long straights (even during overtaking other AI), and the gap barely changes as long as I've already reached certain speed (320-330kph), it's a demonstration of how to effectively use ERS, not just rush in and drain-it-all regardless of situations, you have to wait or create opportunities, starts recharging as soon as you know the move can't be done or is already executed, it's a patient game whenever you're part of the DRS train.
Regarding the Hadjar battle on Lap 5 of Canada, I didn't have DRS, so of course he was gonna gain at me because that's the intended mechanics of DRS, and even that it wasn't enough for him to do so whilst I managed to overtook him on lap 4 where he was in my exact same situation on lap 5, it was all done by having better exit and usage of ERS.
Also, the 0-0 wing setup is actually responding to some other comments here, I didn't want to make so many replies in fear of them looking like spam.
Edit:
I see what you meant by him coming back at me at the end of lap 4, but that was a bad exit, he was already right up my gearbox to take full advantage of the slipstream, and I even disabled the ERS because I know even then he wouldn't be able to make a move as long as I stay on the racing line (just like Oscar irl this year against Lando).
At the end of lap 5, where the gap was about the same as before, but he even had DRS this time, and still wasn't able to get ahead before the finish line, because I actually use my battery this time.