I don’t think there is hard fast rules as it depends of amp draw, motor stall draw, current battery volts, temp, etc. For example, I noticed on testing 7.2v batt and bigger motors, I had to add ~200ms delay between full forward and full reverse - which causes max amp draw. Same with dead stop to full speed can be same as Stall draw. A high draw leaves little amps for fez, which can cause a low power reset as no power left. You can compensate for this with a diode in series and ~1sec of capacitance in parallel between motor supply and fez input (so the fez can power from capacitor during high draw). One street-fix is to try to avoid the issue with ramping delay to limit large current draw. You could do a bunch of math, but I would just experiment a little until you find the spot.