I really like Pongy F. It's an unprecedented driving track, with margins as thin as the track itself. Some insights:
The infamous S-bend at the start is best countered by actually not boosting that much beforehand. It's easier to brake and rotate when you're not already screaming past the sound barrier. Shocking, I know, but with how the game teaches you to always be boosting, this common wisdom is rare.
The embankment at 00:26 does half the steering for me, and lets me take a much more aggressive line. From there I keep drifting the ship for a smidgen more speed, and to get myself in a good angle for cutting through the next corner and into the hairpin.
The turn at 00:45 is a mystery to me. My runs resulted in a time differential of about six tenths (this run was my fastest, and almost definitely what made this an improvement over my PB). My working theory is to brake as late as possible (again, duh) but your counterstrafing into the corner should be done well in advance of the braking. Basically, try carry momentum as deep into the corner as possible.
A slight delay on reactivating the boost afterwards, just for that tiny bit of regen so I can boost all the way into the next corner. I go off the track here because gravity is a speed boost.
About 5 hours of grinding done over multiple days, all on this track to test out square deadzones for the analog sticks. Me likey :)