Go from Babyface to the ADI-2 and from there to the Cranborne and from there back to the Babyface.
Set up the AdI-2 to Digital through mode.

Page 42 user manual ADI-2 Pro

17.5 Digital Through Mode
This additional mode is a manual option only, it is not available via Basic Mode Auto. It has to be activated manually by selecting Basic Mode – Dig Thru.
The purpose of the Digital Through Monitor is exactly what its name describes. A single digital input signal is passed through the unit and can be monitored on the analog outputs at the same time. Automatic clock and source selection of the digital inputs plus internal D to D routing allows to insert and monitor AES, SPDIF or ADAT signals. With ADAT only channels 1/2 are monitored, but all 8 channels are passed through. (Exactly what you are asking for. Isn't that cool !)

Nothing to lose. The converter remains in it's full functionality and quality.

I would have recommended a larger interface here as well, just to add more structure to the setup and also allow for double-speed recording, just as Jeff recommends.

But I don't understand what Jeff is saying exactly why that wouldn't work.

Maybe just give it a try, the proof of the pudding is in the eating and report back, whether its working this way.

You can use either Craneborn or BBF Pro as clock master.

a) Using the BBF Pro as clock master has the advantage, that switching between 44.1 and 48 kHz will happen automatically, controlled by the DAW/application.

b) Using Craneborn as clock master might have the bigger benefit that A/D conversion might benefit from using Craneborn's own clock for the conversion. Babyface Pro FS and ADI-2 Pro FS are excellent clock slaves by SteadyClock FS technology and will reduce/remove any clock jitter. The ADI-2 Pro FS's will use it's own FS clock even if it is clock slave because of it's special design.

As waedi told, try ADI-2 Pro in digital through mode .. the worst thing that can happen is, that it works this way.

BBF Pro FS---ADAT OUT--------->ADAT IN---ADI-2 Pro---ADAT OUT--------->ADAT1 IN---Craneborn
                    ADAT IN<--------------------------------------------------------------ADAT1 OUT

Future update. I eventually did purchase the Fireface Ucx II. I now have my ADI-2 Pro fs r connected to the Fireface UCX II via AES/EBU and my FireFace connected to my Cranborn 500ADAT expander vis Toslink. TotalMix handles all of the routing. One thing I am interested in is how to best utilize the analog inputs on the back of the ADI-2 Pro and ways to optimize my setup. Any ideas or suggestions are welcome. Thanks.