Question

Does "realtime processing" option in "export mixdown" use external clock source (from selected interface), or internal S14.5 engine? Does the mixdown benefit from a good external clock, or is it still "ITB"? Thanks!

Answer 1

If the audio device is locked to an external clock, then yes, the external clock would be clock for everything.

Does the mixdown benefit from a good external clock,

An really good external clock may yield some improvement, it the system or audio device clock is really poor with lots of jitter and the external clock is extremely accurate (expensive).