Well, that was an interesting shift. I ended up working on sosreport only.
I started looking at the first bug in the queue, which had lots of history and led me to the last bug in the queue 
After working my way through the long history of that, I sponsored it for Oracular, Noble, Mantic, Jammy & Focal, after some tiny fixes.
That finally allowed me to sponsor that tiny sosreport fix for Bionic from the first item, too:
Both sosreport items are now handled and Sponsors unsubscribed.
So long, and thanks to @arif-ali for the IRC assistance!