If the ESC needs to sense the state of the motor's rotation to operate properly, doesn't it follow that trying to run multiple motors with one ESC could be problematic? I have an RC blimp (homebrew) that I built with a friend about 40 years ago, and the 4 motors, 6v hobby type, are all wired in parallel to a traditional pulse width speed control. If I update these motors to modern brushless, what do I need to know? The main reason for the upgrade would be to save weight, which is critical, so multiple ESCs would probably not be an option. Any thoughts?