Is screen mirroring only possible on enabled devices?
Mirroring, or MiraCast is actually not fully supported on Android, this has lead Google to build their own mirroring software... 

MiraCast never really worked on Android, there's always a resolution problem because android isn't designed to OutPut video on different resolution's.  

The solution is sort of a screen recorder that utilizes WiFi and software to show the screen recording on a computer or T.V.

I'm sure that it can be enabled on any device that has had MirrorCast  in the past.  

For example, Android 5.1 and up have the option to mirror removed completely while they work on a new version designed for android.  

You can enable the old MirrorCast using some build.prop tweaks, however it's extremely unstable, Hence the removal in the first place.