There is no need to compile the editor just to change the compiler setting. In your project directory update the following files:
File: Config/DefaultEngine.ini
[/Script/WindowsTargetPlatform.WindowsTargetSettings] Compiler=VisualStudio2019
File: Config/DefaultEditorPerProjectUserSettings.ini
[/Script/SourceCodeAccess.SourceCodeAccessSettings] PreferredAccessor=VisualStudio2019
That should let you compile with your chosen version of visual studio instead of doing it twice.