Sure. After plugging in the Motu M2, it works.
I suppose there are issues with the Apple USB-C dongle/DAC (or maybe an issue with the USB-A to USB-C connection, but I sincerely doubt this hypothesis and lack any other equipment to test with). (After further research, it appears I’m not the only one who’s ran into this exact issue: RoopieXL with Apple USB-C DAC - #5 by Daniel_Zacarias)
Not sure if there’s anything left on RoPieee’s side then, since I assume this issue would be with shairport-sync and not RoPieee XL.
[EDIT: For those reading in the far future (6+ months from now), this issue may be obsolete. Following this GitHub issue: Apple DAC fails w/ *fatal error: The output DAC can not be set to 44100 frames per second · Issue #1504 · mikebrady/shairport-sync · GitHub, it directs to a bug report for ALSA: 217501 – Apple USB-C 3.5mm dongle cannot output 41000hz. It appears to be selecting a BADD config instead of the UAC3 config, both of which are present. You could, theoretically, use usb_modeswitch -v to change the configuration manually to #3, which is the UAC3 config (that properly supports 44.1khz). Theoretically, the RoPieee XL creator could attempt to insert the udev rule listed in the GitHub config, which could resolve the issue, but that’s a risk and reward assessment left for the creator to decide. I wouldn’t mind testing such firmware though.]
Any recommended DACs around $10?