I2C Expander

[XORadmin]

I have the I2C expander working great with the following setup…

In skiff case:
Nerdseq > MULTI-IO > I2C-B > F8R

The I2C-A 3.5mm TRS on front of MULTI-IO > XOXO MIDI I2C in larger case > Just Friends > Disting EX
The Disting EX is also set up to be controlled via MIDI using XOXO.

I’d like to add an XVI desktop faderbank to the setup, but will this work over I2C? Could I use a headphone splitter to attach additional 3.5mm I2C using the front panel of MULTI-IO?

I2C-A 3.5mm > splitter > XOXO & XVI?

Or would I just have to use the XVI via MIDI and set that up in Mappings?

A headphone splitter works in general. 
But they are other issues here which are in the way if you want to use the XVI also in I2C mode. 
There is very much data needed if you use the XVI in follower mode since every fader is being polled all the time. That means that there is not too much data bandwidth left for the other I2C modules you want to control on the same port. I do not recommend it.

If you can change the address of the f8r and XVI then you could use both on one port in follower mode. That would work fine.
And else indeed midi just works fine as well.