You make a good point; all consumers in the group will need to be finished processing the stash topic before consumption of the main topic can resume. Initially the solution had specified a manual step—monitoring until consumption of the stash topic was complete, and then switching the consumer(s) to consume from the main topic. Later I got to thinking: why can't the consumer switch automatically? I guess that's why. 🙂
It might also make more sense then to deploy a separate group of consumers for the stash topic; let that group run, shut them down when they're done, then spin up the main consumer group.
Thanks again for the feedback; I'll probably make a few adjustments to the article.