I2C: Do I still need pull-up resistors if I use a logic level converter? I
Apart from performance note the following:

the converter has usually 10K pull-up resistors from both sides as in the following figure taken from https://www.hobbytronics.co.uk/mosfet-voltage-level-converter:


you do not need a converter for each device since I2C is a bus (you may need to use more than one per signal depending on your power assessment):