Good Afternoon, I think it would be nice to have a standalone software to develop, test, and insert revit families outside of the Revit UI. The main benefit to this would be that it could be a lightweight program that could include the ability to select Revit version and family type all through drop down menus without the need to open multiple full versions of Revit. This is useful when you have multiple projects in various releases that are all active.
Here is a link to a basic Gemini coded UI that describes my idea better: https://g.co/gemini/share/26fe2fe44791
Best regards! Stefan Eitnier