The obvious problem is that these movements for an autonomous, independent or satellited Rhineland (without much of an unified perspective) did not have popular support to begin with, rather coming from an urban upper-middle class fear of "Prussian" (i.e. authoritarian and militaristic) political hegemony. The German national identity was very much firmly rooted in the region, with much less rooted-down regionalist tendencies comparable to, say, Bavaria.
The other issue at hand was that, while you did have a significant part of French political and diplomatic circles musing about creating a distinct Rhineland autonomy (or even independence) especially in the context of a French-led custom union, that momentum had passed with the Paris Conference and the realisation that such grand plans had zero British or American backing. For those that didn't got the memo, the diplomatic failure of the Ruhr occupation made it clear.
I couldn't find much regarding the popular support of the Ruhr occupation in France but what I got gives the impression of a relatively lukewarm take on the intervention : active support (largely on nationalist grounds) or opposition (largely communist and somewhat pacifist) remains fairly uncommon and while there's no movement for the return of troops, there's no popular perspective on the autonomisation or sattelisation of Rhineland, something that is essentially restricted to military or politic circles.
Now, it doesn't makes it the possibility unfeasible, but you'd have to rely on a perfect storm in Germany that would not only push more popular, or at least in civic society, in Rhineland but as well more French commitment necessarily tied to British at least passive support.
IMO, a key feature would be the establishment of an authoritarian post-war Germany in the early 1920's unwilling to compromise with the post-Versailles order.
I don't know of inter-war Germany history enough to say how a Kapp Putsch or another far-right coup would have been successful but the military disorder plus an urban fear of "Prussianism" could have helped regionalist/autonomist to take more on-the-ground control with maybe not a French backing but benevolent passivity in a first time. A militaristic and extremist Germany might be what would be needed for Britain to say "f**k this" and give French an assentment to support not a full-blown military intervention, but a securisation of the "Rheinish margins".
I wouldn't think that these movements would endorse anything "un-German" : rather, some sort of a proto-FRG opposing democratic, bourgeois, liberal, federal values against "Prussia"-dominated Germany; with French backing looking not at annexation but backing a closer Rhineland with a "Rheinish mark" (envisaged in 1923 IOTL) and in sort of a political/custom sphere.
