It certainly is possible to set up 2 routers with a back to back serial connection and to configure the link as frame relay. But since there is no device to provide the Frame Relay switching, the ability to really emulate Frame Relay is pretty limited. I am not clear from your description how closely and exactly you need to emulate the Frame Relay environment.
Your configuration has 4 subinterfaces (with multipoint and point to point). You might be able to emulate 1 of the point to point but I think you can not really emulate the multipoint. And I do not believe that 1 router back to back can possibly emulate 4 subinterfaces.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...