So, this isn't so much an issue but a caution to others -- avoid Serial.begin() if you have ez.begin().

On the https://github.com/M5ez/M5ez/blob/master/README.md page there are FIVE mentions of Serial.println and never once did I read them closely enough to notice there was no Serial.begin. In fact, if you include Serial.begin in your sketch it dies a horrible death: parses, compiles, uploads, but it bombs out at runtime when it hits ez.begin().

I love M5ez and my one suggestion might be to add some note in the README.md about not needing Serial.begin OR perhaps consider a slight improvement so that ez.begin() gracefully avoids serial.begin() if the user already has made the call.