Thanks. I had another look at the implementation.
I noticed that ?version=alt was previously provided as a way to preview the alternate admin dashboard, but that it was removed here:
Am I right in thinking that, while Dashboard improvements is still Stable rather than Permanent, setting Enabled for → No one is now the only supported way to get the legacy admin dashboard?
In particular, I quite like the old happy/neutral/sad update-status indicator.
When dashboard_improvements becomes Permanent, is the intention to remove the legacy dashboard entirely, including that update-status presentation, or will there be another supported way to view that information?