More follow on from MDL-70444. This page is still breaking at high scale. Ideas:

• order by user last login timestamp so deltas work better - if it dies, and you re-run it, and you are on a prod site where lots of people are actively logging in and their dashboard is being re-setup again, then it still runs as a delta from last time except the delta keeps going back up. To mitigate this, lets run the dashboard reset in order from those whose last login is the older to the most recent so we should avoid reprocessing the latest ones until the last.