Three hours in to the upgrade now, BTW.
It might be an idea if an interstitial page with progress bar could be added at the upgrade step, plus more prior explanation in the notification why an upgrade is required, and maybe a link out from there to the page you mentioned.
No idea when this is going to end, or if it will just crash under the load.
Incidentally, most of the v5 changes don’t seem relevant to me.
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