I think found a fix for the issue with the KQED Sonos audio stream that was causing frequent dropped audio.
The issue itself is clearly related to the feed from KQED to Sonos. I don’t have an issue with other Sonos stations, or with streaming KQED outside of Sonos.
To solve the issue I created my own radio station manually, directed to the primary stream at https://streams.kqed.org/. I did this using the PC desktop app, but I think it can be done on the mobile app as well.
When searching for a solution I found other people having the same problem. Maybe this post will be helpful to someone.