Yes that is a workable solution! Rather expensive though.
The item we want parallel to the original brake switch is the item in the Rotlicht called 'G-Force sensor for brakelight'.
If we can find an adjustable G-force sensor and connect that sensor to a relay which provides 12V to the brake light we are successfull.
I am not electronically inclined but found search tems like accelerometer / tilt switch / ball bearing switch