[ScorpiusWireless]

Thanks Mr A.
Facts are there is not one bit of evidence that a sensored BL motor has been used in any analogue or digital competitions. And there are two Euro companies selling slot car  BLs. One is custom made (way to go), the other an existing BL rebadged.
Neither are sensored. 
As proven we can add hall sensors to anything. But the firmware required is astronomical.
The thing is you’ll need a suitable small ESC designed and manufactured and the firmware. And unless you have decades of actual firmware experience and knowledge it’s never going to happen.
Of course you could attempt to add feedback to a sensorless BL but it’s not even practical.
Can you imagine 3 hall sensors with 3 wires each, 9 in total in a tiny slot car compartment? Plus 3 motor wires? I can’t.
A small PCB? Not practical. An ESC, a digital car decoder and a seperate board for sensors, then possibly a light board in one car? 4 boards?

The issue here is there are no purpose made sensored motors for slots, so why make a product that will never sell?
Now if 50% of motors were sensored then we would go with sensored. But there are not. 
Purchasing 3rd party products and posting endless posts with lots of pics won’t achieve anything.
You need an experienced engineer, a dedicated PCB and lots of firmware.