Switch an opened .blend project to a different App Template (with all of its workspaces)?

Let’s say I have 2 custom App Templates:

  • one for 3D Modeling (with a few workspaces dedicated to the specialized tasks of modeling)
  • one for Video Editing (with a few workspaces dedicated to the specialized tasks of video editing)

The main one is 3D modeling.
Now if I want to open a .blend file project that only has movie clips I want to video edit, I’d like to be able to switch to the Video App Template (with all of its workspaces), so I can start working on the movie.

The problem
The problem is I can’t fully switch to a different App Template without creating a New File (that closes the current project).

The “Load UI” option doesn’t work here either, because:

  1. I don’t navigate from Blender to open my files. Usually I double click the file from the Windows’ explorer.
  2. The file might have been saved with an ancient UI configuration and I tend to adjust my UI from time to time so the small UI adjustments I recently made don’t get taken into account. It also might have sidebars opened and generally messed UI.
  3. This only opens a new workspace tab in the General app template, while I would like to switch to the the full App Template’s workspaces .

Temporary solution
What I tend to do for now, is to open a tab by clicking the “+” (for Add Workspace) and select the workspace I need, but it just gets added to the General App Template behind all the 3D modeling workspaces.

So the question is: is there a proper way to open a .blend file and switch the project to another App template (with all of its workspaces)?