I've remixed the laser filament sensor housing and added a placeholder for a micro switch.
The laser sensor works great for most filament types, but not so well for some others. I barely have issues with extruder grinding, so my main concern was running out of filament and this is where the switch does a great job.
A microswitch is easily added to the laser sensor pcb and the laser sensor can be turned off for filaments that the laser doesn't detect that reliably while the switch will still detect when running out of filament.
I've also increased the distance from the filament centre to the PCB to 9mm and that seems to help with the measurement accuracy.
To turn off the laser sensor and only rely on the switch use the S0 parameter with the M591 command. Don't forget to set P6 to enable the switch (P5 is for the laser filament sensor without additional switch).
Note that this is for V1.7 of the PCB and there are minor changes to V2.0
You can find the design here https://www.thingiverse.com/thing:4306968
