For those having similar issues to this one, it appears that Big Sur 11.3 (or a change to the Boot ROM/iBridge, or something else) has lessened the frequency of drop outs for my hardware. It's still not perfect, but a little better. The drop outs only occur for about 0.03 secs where before they were much longer.
Connection path:
DS1 -- CalDigit TS3+ Thunderbolt hub -- MBP16
Here's my config:
Hardware Overview:
Model Name: MacBook Pro
Model Identifier: MacBookPro16,1
Processor Name: 8-Core Intel Core i9
Processor Speed: 2.4 GHz
Number of Processors: 1
Total Number of Cores: 8
L2 Cache (per Core): 256 KB
L3 Cache: 16 MB
Hyper-Threading Technology: Enabled
Memory: 64 GB
System Firmware Version: 1554.100.64.0.0 (iBridge: 18.16.14556.0.0,0)
System Software Overview:
System Version: macOS 11.3 (20E232)
Kernel Version: Darwin 20.4.0
Boot Volume: Macintosh HD
Boot Mode: Normal
Computer Name: mymbp16
User Name: myusername
Secure Virtual Memory: Enabled
System Integrity Protection: Enabled
Time since boot: 1 day 15:54
AppleUSBAudio:
Version: 405.39
Last Modified: 1/1/20, 2:00 AM
Bundle ID: com.apple.driver.AppleUSBAudio
Notarized: Yes
Loaded: Yes
Get Info String: AppleUSBAudio 405.39, Copyright © 2000-2021 Apple Inc. All rights reserved.
Obtained from: Apple
Kind: Universal
Architectures: arm64e, x86_64
64-Bit (Intel): Yes
Location: /System/Library/Extensions/AppleUSBAudio.kext
Kext Version: 405.39
Load Address: 18446743522231001000
Loadable: Yes
Dependencies: Satisfied
Signed by: Software Signing, Apple Code Signing Certification Authority, Apple Root CA