On the note of testing I2C devices: hook them up to any VGA or HDMI port and you are good to go with a complete OS. I even have some sensors running that way on my server for domotica needs.
https://mitxela.com/projects/ddc-oled
DDC is how your OS reads the list of supported resolutions from your display and is present on VGA ports as well. It's just a low speed i2c bus and can be used for other things :)