[dominicperry]

This is unlikely to work well.
1) The UAD Satellite already has a high latency compared to an Apollo interface.
2) The Carbon hosts the plugins used during tracking on the DSP in the Carbon - so round-trip latency for the Carbon isn't an issue, which is important because using a PT plugin natively (i.e. on the computer) requires a round-trip from Carbon to computer and back to Carbon, which isn't particularly fast (just the Carbon AVB round trip is about 6ms minimum).

So - if you want to record a live vocal with a single AAX-DSP plugin on the Carbon and a single UAD plugin on the Satellite, you will suffer both the Carbon AVB latency (because the Carbon has to hand the monitor signal back to the computer in order to get to the UAD box) and the UAD Satellite round trip.

Mic -> Carbon (with AAX-DSP plug) -> AVB -> computer -> PT -> Thunderbolt -> UAD Satellite -> Thunderbolt -> PT -> AVB -> Carbon -> headphone/monitor output.

Contrast this with just using Carbon and AAX-DSP plugins.

Mic - > Carbon (AAX-DSP plugs) -> headphone/monitor output

I'm guessing that the first chain is probably 10-15ms (depending on sample rate and which plugs you choose and assuming your computer is fast enough)
and the second is only 1-2ms, depending on sample rate and which plugs you choose - (the Carbon-only scenario doesn't rely on computer power, so only sample rate and choice of plugin makes any difference to the round-trip time).

That's not to say that using a UAD Reverb or other similar effect isn't feasible.

All the above is related to tracking - for mixing there should be no problem in using native plugs in PT and UAD on the Satellite. You would not normally use DSP plugs on the Carbon when mixing, regardless of whether UAD is used. The DSP on the Carbon is intended for tracking only.

Dominic