Great article, some comments:
I feel this chapter could add some more information.
As for example common differntiators of popular microswitches etc.
Also the so frequent happening double click issue could be added.
It should maybe be added that SROM is provided (and developed) by the sensor manufacturer and not from the mouse manufacturer/brand.
Also the srom of the sensor ic is not necessarily a part of the firmware update.To upgrade the srom later the firmware/hw needs to support that feature (not all mice do, even though they support updating of the firmware).
There is no risk in updating the firmware if the implementation is solid. Even power outtage or similar should not brick the mouse. However you would need another mouse to start the firmware update of the "temporarily" bricked mouse again
Unfortunately not all firmware update routines are as solid as they should be so in some cases of poor implementation you actually will brick your mouse - blame the manufacturer.
Other topics that could be added would be wheel/mousefeet/cable and maybe even wireless