If your laser is connected to D11 then it is already configured for 0.9.
Does your laser module have a small switch on it?
Do you know if the laser runs from 12V, on your original board it appears to say 5V. If so you may have problems with the new board you posted as it doesn't have a buck converter to provide the 5V output.
The MOSFET is an electronic switch of sorts (at least in this application) that is used to control the laser.