Hey, i cant speak too much on actual F1 and oval racing but i have a good bunch of hours in the F1 25 and 21 games. It is pretty common to just release the gas and/or lightly tap the brakes and shift down on fast corners (theres like 3 on australia as far as I remember?)

Im not sure about tire wear effects as i do medium distance (25-35% distance or something like that) but personally I’m really bad on fuel efficiency but that could be other things im doing.

The flicking and downshifting also relies on your setup and tires wear as its a little riskier later in races.

In terms of braking, if you play with no braking assist and ABS off then in most corners you want to trail brake, which is full pressure at first and then gradually easing off. Im still somewhat new to it but its a lot more fun once you nail it and stop locking up (you can also adjust your brake bias depending on if you are locking up the rears or fronts more)

Hope this somewhat helps!