The Xracer Quadrant BLHeli ESC from FPV Model does something I've never seen before. It lets you decide whether to install it on the quadcopter's arms, as usual, or you can combine the ESCs into a 4-in-1 board that fits in a 36mm stack. The ESC takes up to 6S, runs BLHeli_S, supports up to DSHOT600, and costs about $13, so... WHAT MORE COULD YOU ASK FOR???
This ESC is scheduled to release for sale TODAY, December 26, 2016. Buy it here: