They would work to an extent. My DI has an "epoxy" headliner which looks to me like rhinoliner sprayed onto the headliner form. It might not be that simple but it sure looks like it. It was done before I got the truck so I am not sure of the process. They used a flecked tan material that looks great with the interior.
Are we talking about the sagging thin liner that falls from the cardboardish pannel. If so i have sprayed 3m glue threw a small hole in the sagging areas and let the glue dry before working out the sags. If im off topic here please dissregard my ideas.
I pulled mine (2K D2) a couple weeks ago, stripped and painted it. It was a laugh to do, very easy and looks great. Don't skimp on the prep, as the fibreglas will show any leftover foam.