Oh wow, I missed that the graphic itself has that described.
The csv file is correct, and most, if not all alternate functions available on the Daisy Seed. It also has the port/pin combo listed.
Unfortunately only two I2C peripherals are fully exposed on the Daisy Seed. We’ll fix the diagram (and add the port/pin information to it) ASAP.
The processor’s datasheet has the complete list of alternate functions for every pin on the chip.
Though, I2C is designed to support multiple devices per bus. (Up to 64 devices on each peripheral) as long as they have their own addresses.
What devices are you trying to connect? You may be able to make this work with only one or two of the peripherals.