hGPIO pin5V(91) are remains of previous version created during development. They are not necessary now and will be removed in further releases of hFramework.
IMU is connected only to
hSens2, it can not be affected by
hGPIO pin5V(91) is for powering on and off all sensor connectors.
Could you explain what do you mean by:
make the connection to hSens2 variable in the code not a constant in various files
It would be great if you specify more precisely what do you want to achieve.