Hello @xxx_yyy
I stand corrected. My apologies. You are absolutely correct: IMU INT in M5StickCPlus2 is not connected to anything. (I was looking at the RTC INT.)
That said - and to answer your original question - yes, it is possible to connect the IMU INT pin to an ESP32 GPIO. Please see here.
However it would only allow to wake ESP32 from deep/light sleep, but not to turn M5StickCPlus2 back on from being powered off due to the fact that IMU is powered from 3.3 V (and not like RTC from VBAT_IN).
Thanks
Felix