i have a castle mamba max pro linked to 27T brushed motor in the reversed brushed mode on a rock crawler (wheely king), ESC crawler mode, 213% drag brake crawler full on, crawler reverse, etc....
when programmed with firmware 1.28 :
1 - connection with the field link by itself (not usb) makes all the lights of the field link flash in a funny way.
2 - running the system yields a random loss of control in both forward and reverse throttle positions. randomly while playing, the esc makes the small car suddenly run +/- 50% power constant and can NOT be stopped remotely by any other means than turning power off.
The first time this happened the car ran straight to a wall and damaged some gears as i heard it "screaming & ticking", quite unpleasant .
of course i know these are beta firmwares (1.28 & 1.27) and that there are surprises but that one really was a good one!! a ghost remote control car running in my room!!! aaaaahhhhh
i rolled back to firmware 1.26 for use with brushed motor due to these problems and the device seem to run normally as before.
Firmware 1.28 with the brushless 7700kv does not have the same bug. i just noticed the new feature that allows to limit the output power to 100-10% yields a problem of proportionnality, the lower power you command would have a gap of reactivity which can be quite important. more generally, the lower speeds of the motor are not proportionnal at all with the device. it suddenly jumps whatever the settings of power management.