PlayStation Vita hasn’t even sold 15 million units. It’s probably the last platform you should even be considering.

PlayStation Mobile was discontinued. You now have to do more work to be granted into the PlayStation walled garden. Which I think requires a business and not an individual, unlike PSM (I think).

MonoGame can be ran on PlayStation Vita and PlayStation 4.

MonoGame is a powerful cross platform solution and any platforms it lacks can be addressed by the community or yourself.