Q: “How do I adjust my optimal turn-in and braking for an off-camber corner to minimize understeer?”
A: This is a strong case for the value of the timing and rate of release of the brakes. Understeer when entering a corner can be caused by not having enough load on the front tires – not trail braking enough – or from too much load on the front tires – too much trail braking, asking too much of the front tires.
An off-camber corner is going to exaggerate the understeer, so getting the timing and rate of release of the brakes just right to ensure the front tires are loaded, but not too much, is critical. Unfortunately, there is no magic, one-size-fits-all solution to just when and how you should release the brakes for all off-camber corners! You have to get good at adapting the timing and rate of release to the needs of the corner, so deliberately practice this – experimenting with different timings and rates of release is the critical.
For more information how to adapt the timing and rate of release of the brakes to manage understeer, go to https://speedsecrets.com/q-how-should-i-practice-and-get-better-at-trail-braking-and-my-brake-release/
Ups are downs are as much a part of the corner as the left and right. If the camber is causing a problem, I simply modify my line to avoid the problem. e.g. turn in earlier, later, brake earlier, later, or both to not ask the car to do work on the off-camber part. Start from a different place. Brake longer and less. Experiment and see what works. It’s a lot like skiing. This is what makes it fun!