I think that’s an unnecessarily drastic step.
If you look in %APPDATA%\Steinberg\Dorico 3.5 (Windows) or ~/Library/Application Support/Steinberg/Dorico 3.5 you’ll find various XML files for saved Engraving Options, Layout Options, Notation Options, etc., plus the file userLibrary.xml that contains any notational items you’ve saved as defaults. You can move them out of the way or delete them and Dorico won’t find them next time you start it up.
However, I’m 99.9% sure that the slur problem you encountered in your other project is user error of some kind, though I’m sure your assessment would be different.