For the ADAU1701 project, the sampling frequency selection window shows drop down selections up to 768KHz.
Datasheet for the ADAU1701 says max sampling of 192KHz.
I tried setting the sampling frequency to 768KHz after adjusting the frequency related parameters by giving them the correct multiplying factor and it seems to work.
The sound seems noticeably rich.
Is it recommended to use ADAU1701 outside the datasheet specs of 192KHz?
As you suspected, the ADAU1701 cannot operate at 768K. SigmaStudio makes this rate available to support the new ADAU1777. Like the ADAU1772, this chip features very limited signal processing, but does it with near-zero latency. Its primary application is in noise-cancelling headphones.
The drop-down Fs menu atop the schematic only adjusts how SigmaStudio calculates time constants and filter coefficients -- it doesn't actually change the DSP's sample rate, which instead is handled in the HW Configuration / Register Settings window.