I know opinions of 10.69.3.1 are a dime-a-dozen these days, but I think it's still worth saying I'm relatively pleased with the improvements. Conservatively I'd say that it's about an 80% improvement in acceleration and braking in difficult spots (speed limit changes, cut offs, merging, last minute red lights), and a 50% improvement in lane selection. I still had one aggressive application of the brakes this morning, but it was at low speed after successfully routing around a landscaping truck that had stopped in a right turn lane. And I still had to disengage to manually put my car in the correct lane twice. But they're both situations with counterintuitive intersection design (one that randomly splits into an unmarked bus lane before rejoining the main road and immediately losing a lane, and one that requires the car to be in the far left turn lane, despite an immediate right afterwards).
So it's only failing in situations that a driver unfamiliar with the intersection would also often fail at. I don't think any additional work on lane guidance will fix it, these particular intersections will likely need Tesla to implement fleet learning or memory of past traversals of the intersection in order to solve these.