I'm going to guess that nobody has successfully mounted it into a 1/12th scaler. It is waaaayyyy too bulky. I'm running a Novak 1s in a 12R5, and it just barely fits.....and the Castle is much larger than the Novak.
The other issue could be the price. The Novak 1s combo w/ 13.5 BL motor, and as of today, the combo is only about $20 more than the Castle ESC all by itself.....and the the Novak ESC by itself is $25 less than the Castle.
The biggest benefit to the Castle is it's good for 1-6 cell operation, which means more flexibility to move it around between different cars/different classes.
SC10.2, RS, 13.5
SC10B, RS, 13.5