Dave,
All I can say at this stage is who is the manufacturer of the dado blade?.
Also have you contacted Makita to see if this sort of modification is even safe?.
Reason I say that Dave is because if you disable the electric braking system, you could also be disabling any sort of speed controls too.
The speed and stop systems could be controlled by the same Triac/Diac or SCR's.
To have an out of control Series motor would be very dangerous. [Linked Image]