Errors or issues during or after updating devices with certain Conexant audio drivers -- Conexant or Synaptics audio drivers might receive a stop error with a blue screen
Errors or issues during or after updating devices with Conexant ISST audio drivers -- Devices with affected Conexant ISST audio drivers might receive an error or have issues with Windows 10 2004
Issues when using Microsoft IME for Japanese or Chinese languages
The "Windows can't verify the publisher of this driver software" or other errors caused by installing incorrectly formatted third-party driver issue has been resolved.
It's not too surprising that the 20H2 update doesn't have many issues because it shares most of its code with the 2004/May Update. And that feature update has been through months of Microsoft working to fix a lengthy and changing list of known issues.
Microsoft will likely be updating the Release Information page as Windows 10 20H2 rolls out more broadly, so if you're blocked from getting it or having issues with it, definitely check the page when trying to troubleshoot.