Your development has been impressive. When you can see a beta version? I recently changed my old AIW importer and change to vector calculus and several lines of complex mathematical calculations were reduced to one line!. I also added import pitline and corridors. Import something that is already done is easy what you are doing is much more complex well done.
if use a spline with two bezier points in a turn. Can determine the apex by a cubic Bézier. maybe helps.
That's the base procedure if we were looking at isolated corners, correct? How about corner combinations and corners where early/late turn-ins become more efficient? Can you assign weights to move the apex, for example if a corner has a tight radius and long arc (like a hairpin corner) you'd move the apex towards corner exit a bit to compensate?
I'm looking forward to the lines your algorithm will come up with for the last two corners where it has identified a double apex each.
Not too shabby. It looks like the path is not extending to the outside after a turn enough. On entry it does, but on exit it mostly stops using the available space around the center line. It's especially bad from the chicane to the final corner. In the combination the AI would lose massive amounts of time by not utilizing then available space for a wider corner radius and higher cornering speeds. Looking forward to the second try.