So you can't use other file providers? That tech is really stable now, I've been using it for years to edit a git repo inside Working Copy or files inside other

So you can't use other file providers? That tech is really stable now, I've been using it for years to edit a git repo inside Working Copy or files inside other apps using yet another set of apps (Textastic, iA Writer, even vim inside a-Shell). You should really consider reviewing that viewpoint.