Now, I kind of fixed this last month by adding "Console Sections" to the Jenkins configuration, which is able to collapse all this nicely.
The only problem is, they apply only to what is currently on-screen. And by default Zuul/Gerrit links to the trimmed output showing the last few hundred lines only.
This means the start of the long setup output is outside view, and thus the "Section" regex isn't matching because it's not there.
Let's try to fix this by overriding the links in Zuul/Gerrit to point directly to the full output.