After enabling the RPM measurement on a Quad-X craft that flips on takeoff, I see that the front motors (#4 and especially #2) consistently deliver higher RPM for the same throttle input. Here are screenshots from Betaflight Configurator:
My first thought was that this could be related to the voltage drop in the wiring (the rear motors, #1 and #3, have longer wires), however, that doesn't explain a particularly high RPM value from the motor #2.
Is there a way to "equalize" the RPM output of all my motors in software? Why is such discrepancy even possible in the first place, when Electronic Speed Control must by definition achieve constant RPM, increasing the voltage on a motor with higher friction or poor wiring?
PS. My ESCs are 20A LittleBee modules flashed with Bluejay v0.16.