ADI 2/4 Pro SE - Use of additional ADAT Channels possible?

Okay I haven't thought about the ADAT output to be honest, but that would be pretty cool to do some daisy chaining and or advanced routing.
Even a fixed definition / ADAT mapping as you described would be cool.

I actually think the first step would be something like an additional option to select which input channel of the ADAT should be used. Or an extended list of inputs. But to keep it simple I think having an advanced option just to select the channels when ADAT is detected would be cool.
Then using multiple ADIs should be possible by using TOSLINK splitters I guess? 8 channels of audio to a splitter, channels 1/2 and 3/4 to ADI A and the rest to ADI B?

So to keep the current input channel logic I suggest of something like this:
I/O Menu --> Settings Page --> add new Menu Item (per I/O Page, Ph1/2, Ph3/4, Line ....) "ADAT Channel" with Option 1/2, 3/4, 5/6, 7/8
If Source == SPDIF optical AND ADAT is detected --> Use the selected channels from the stream.

I guess that the remaining problem will be how to handle SMUX modes?

Thank you for the suggestion, but I am aware of the possibility to use another cable for the second input.
My point is that this would be a cool feature to just use one toslink cable from the Fireface to the ADI.
And again, this is just a guess, but I expect that the protocol decoder module used inside of the FPGA is capable of providing the data for the additional channels.

A minimalistic extension would be:
Make all ADAT channels 1/2 to 7/8 accessible from the source selectors.
At 96 kHz and 192 kHz all non-existing channels would be greyed out.

Everything else would stay like it is, including the clock situation.

192 kHz doesn’t make too much sense for ADAT anyway, as it’s easier handled in SPDIF format.

This change would fit to ADI-2 Pro’s and 2/4 Pro SE’s four DA channels.

I'm also thinking about a minimalistic extension as KaiS described it.
And I do fully understand that you do not want to put to much efford into such a specific use case.

For my personal need it would be enough to include an expert setting which lets me choose the ADAT channel to be used at 48kHz per channel.

Also a fixed mapping would help:
Default: just as it is right now
Active:
@48kHz: fixed mapping 1/2 --> 1/2 and 3/4 --> 3/4 or something selectable (but I get that this is additional efford)
@96kHz: fixed mapping 1/2 --> 1/2 and 3/4 --> 3/4 (or if this is also a clocking nightmare: feature not available)
@192kHz: fixed mapping 1/2 --> 1/2 and 1/2 --> 3/4 (feature not available)

But of course a selection of the channel would be the nicest solution.

Sure. But other than on interfaces that offer graphical overviews like TotalMix, here the user stays completely in the dark why something doesn't work anymore. Support nightmare upcoming...

On 2 Pro and 2/4 Pro the source of Phones can be set to ADAT 3/4 as new option. That is a minimalistic solution but still really useful extension of existing functionality, valid up to 96 kHz, mostly avoiding the pitfalls mentioned above.