[baijuxavior]

Create a keyboard mapping for 3dmode like <f1>3dmode</f1>

Play the movie in normal mode by setting 'preferred 3d mode' as None. Then use the 3dmode key just created to select the appropriate mode.

I don't have a full sbs/ou clip to test. If you can upload a small clip sized around 50MB I can check for a solution.