Treaty of Frankfurt is not the Versaille dictat. France could pay. Germany could not and that was intention.Personally I find the idea of greater occupation as mostly potentially helpful for reparations, not reducing the stab in the back. If anything, stab in the back might happen more - "not only did the Jews destroy our great Empire, but they invited in the French/British/Belgians to take over Germany"! Still reparations wise it would do wonders for forcing Germany to pay, like France's reparations in 1871 (when Germany occupied pretty much all of Northern France).
Not that there where any troops left to occupy Germany anyway. So the whole argument is rather moot.