Thank you very much for your answers help me understand this hardware.
Yes, that's my question. Use M5stack regulator to power the M5Stack and not from charger .
In this case and, it is a last question about this, there will be no problems with the USB input if it is powered by an external battery. In some other case I have had problems connecting the USB, because both 5v sometimes are not exactly and that small difference produced power noises by connecting the USB, and sometimes reestorting the unit.