asynchronous USB is the only protocol synchronising the server’s and dac’s clocks
Confused.
Can you explain how does an asynch protocol synch two clocks? Hint: it doesn't.
AES/EBU may have better noise rejection but has imbedded clock signal,SPDif is outdated as well as speed constrained
confused again. AES/EBU is fundamentally SPDIF that is 1) balance and 2) contains optional metadata. Speed constrained? Not for the vast majority of formats and oversampling in even remotely common use....