Maybe it can be done with the approach I am programming here (I have not had the time to set up a proper URL to test it, it does not work proplery on localhost).
In other words: Use the 'first logged in' content rule to create the folder, should be quite straightforward ( ping me if you need to code)
Update: Content rule to redirect to page (Plone 6 Classic) - #4 by espenmn