bad news! my driver is different. my driver is using still using direct drive pwm and using just the RDS on of the mosfet as a current limit.
another issue i have with my driver is that it is only 2 modes (hi and low)
new info: - turns out the third mode is long press for strobe
- my new controller seems to be using a 8mhz controller (AVR?) similar to OP’s
- my driver looks like comfychairs 6LED flashlight No-name '6XL2' dissection
i cant help in re-programming your controller as the micros are different.
on another note, you can look at the pwm using these instructions: Measuring PWM