Thanks. I have no time just right now to look at the details.
On the 1st glimpse the cabling makes no sense to me, for example to chain the Audient Preamp behind the Rosetta AD/DA converter.

That part should look more like this

Digiface USB----ADAT1---------------------->ADAT---Rosetta
                   -----ADAT1<---------------------ADAT----Rosetta
                  -----ADAT2<----------------------ADAT----ASP 880 (clock master)

You need to make the ASP 880 to the clock master,.
Digiface USB has no Word Clock and ASP880 has no digital inputs to receive clock from a digital connection.

The stacking of the two toppings also make no sense to me on the 1st glimpse, but I have no time to look further.

You can make the Audient ASP880 to act as clock master, but from operational perspective it is nicer to make the recording interface to act as clock master, which is connected to your PC. Because then you only need to set the sample rate in the application, then the RME driver sets the sample rate for the recording interface and the digitally connected devices (clock slaves) learn the clock from either Word Clock or digital inputs. In this case Digiface USB has no WC and Preamp has no digital inputs, thus not possible.

A better choice would be RayDAT, but this is a PCIe card.

Regarding clock sync see my blog to get some information: https://www.tonstudio-forum.de/blog/ent … ios-en-de/

Another question to you, do you intend to work at single or double speed.
At double speed (88.2/96 kHz) you only get 4 channels out of one ADAT I/O port, do you need then two per device.