I removed one of the duplicated Open With items by performing a full uninstall removing all settings then using Ashampoo Uninstaller version 8 to remove all traces of EmEditor. I rebooted my computer using Ashampoo Uninstaller to log a new install of the latest EmEditor version 19.7.0. Now open with shows a single entry for “EmEditor Try Icon program”.
Too bad I had to lose all settings, but this worked.