We haven't put much thought into this. But I mean, this is gzdoom. Someone smarter than us has almost certainly ported gzdoom to phones, its not a stretch to think this could run on a phone
Now, this would require you to bake the vertex color animations for every frame of animation; you would need some way to manipulate the mesh data in Unity if you wanted to have any kind of smooth interpolation. But, have a look at the multiAttributeTransfer node here: http://www.soup-dev.com/examples.html That's how I've achieved vertex lighting effects in Maya.
I saw your Realms Deep video and you asked a question about animating vertex colors. This is something I have a bit of experience with. I should preface this by saying that my experience is with Autodesk Maya, not blender. But, the SOuP plugin for in Maya allow you to create effectors that can apply a whole host of vertex color tricks. You could potentially export your meshes to maya, use SOuP to animate vertex colors, and then save that data in an alembic file. Blender can read alembic, IIRC. How you'd get that to unity is a bit beyond me.
