@ajb2k3 thanks for your answer but as you can see just above I already got the answer from another post on the forum.
In fact this is not that simple.
Yes you can flash the device with the binaries found on the MicroPython website but then you only get the basic lib to get access to the ESP32.
If you want to take advantage of all 'surrounding' features like touch screen, accelerometer etc...then, unlike with UIFlow where the libs do encapsulate all those surrounding features, you have to dig yourself and find the correct libs as M5Stack is not providing one.