Ok. So, let me try and rephrase. The Portenta is running at 3.3-V logic. The description on Adafruit's page is as follows:
I2C Pins
SCL - I2C clock pin, connect to your microcontrollers I2C clock line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
SDA - I2C data pin, connect to your microcontrollers I2C data line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
With the on-board level shifter, it should be fine to POWER the module from 3.3 volts or 5 volts, correct? If that's all, it's just a matter of removing R1-R4.