The PWM frequency will not be easy to tune, i believe. From the measurements it is around 1KHz. The only option is to control the duty-cycle of the signal.
For the current regulation, the module uses the IC TP92641 from Texas Instruments.
Based on the scheme configuration (resistors) seems possible to identify what is the theoretical threshold configured for this laser, using the datasheet as reference.
For the other hand, applying 100% duty cycle we can measure with a multimeter the max current (A) flow to the diode.
Based on previous two assumptions, its possible to compute the power (P=V*I) applied.
I don't know the max Current this specific diode can take.
These statements make any sense??
The measurements show the both: control signal (S) and the signal applied directly to the Diode Laser.