Congrats on the improvement you did get.
Many folks have gotten some assistance on Hard Braking and Aggressive Turning by using G Sensor (on Android for me, not sure about iPhone).
I installed and tried numerous g-force sensors and found most had more data than I needed and were hard to read while driving. G Sensor seemed to be the best solution for me and the screenshot below is the whole UI, no menu or other screens, that's it. To use it you start by mounting the phone in your vehicle while stationary and press calibration. You need to press calibration very lightly for it to center the ball. I do this on a level surface but I don't know if that's necessary. You can use this app as a gauge of your braking and cornering.
Here is a link on Google Play:
G Sensor - Apps on Google Play
Screen shot:
View attachment 723255