Solutions
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Eddie Seelke's post in Blank Dashboard was marked as the answerOk, after spending way too many hours rebooting with just one new plugin added I found the issue. It wasn't even a plugin.
Posting the resolution here in case someone else has the same issue.
The problem was in the /boot/config/dashboard_settings.json file. I renamed this file to dashboard_settings.json.bak and the dashboard came right up. Didn't even need to reboot for this.