nice description

also worth emphasising that the sensors are wired using shielded cable all the way into the ECU connector, so you will need to carefully cut through the jacket, and screen to be able to expose the core which carries the signal - make absolutely sure that no wire whiskers from the screen manage to short to the signal core connection.
Alternatively if you are nimble with the right soldering equipment, you can solder the wire to the back of the crimp terminal in the ECU connector without disturbing the cable screen

Also the signal that you get straight off the sensor is an analog waveform that varies in amplitude with speed, the device you connect to possibly may not be happy with that if it's expecting a nice clean digital type squarewave signal.. conversely there is also the possibility of the external device clamping the signal from the sensor and upsetting the ABS system..

These are only possibilities, not neccesarily likely, but worth bearing in mind..