TL;DR From my initial testing, macOS Big Sur 11.1 (20C69) works great with the S3L and S6L.
When I first started testing, I was doing so through the PreSonus SW5E, which resulted in the clicky AVB audio problems I experienced with macOS High Sierra (see my previous blog post on the topic.) After removing the SW5E from setup, everything works great.
|23 Dec 2020||macOS Big Sur 11.1 RC (20C69)||2020.11.0||Yes|
I’ll track macOS Big Sur here, as well as my larger combination list on my wiki (https://wiki.forestent.com/Avid_S3L_and_macOS).