User #1 is
2015 MacBook Pro, Catalina 10.15.7
2x Scarlett 18i20 2nd gen extended through ADAT
AT&T fiber optic, but his home network is complex, with a Cisco router
SonoBus standalone
I'm User #2, 2017 MacBook Pro, Big Sur 11.1
Clarett 8Pre USB extended through ADAT with Saffire Pro 40.
Sonobus standalone, but using Loopback to create a virtual device to integrate the Clarett inputs, Logic Pro X and VLC.
User #3 I think is on Mojave, using an older MOTU interface, using SonoBus through MainStage plugin.
We're all using sample rate 48kHz, audio buffer size: 128, and jitter buffer mode Initial Auto, but other settings produced similar results.