I consider the mental to be a subset of the physical world
I think it might be the opposite. The appearance of a physical world is created by consciousness. One of the reasons I believe this is my understanding of what scientists see when observing the smallest particles possible. I've read that subatomic particles only exist as particles while they're being observed and measured by a conscious being. Until then they're just waves of energy. If this is true then it might also be true that the entire material world doesn't exist unless consciousness is observing it. Consciousness may be the primary foundation of the physical world, not a byproduct of it.
This belief is reinforced in my mind because I regularly experience it firsthand while dreaming. When I'm asleep and dreaming, I may see and talk to friends, ride a bike, drive a car, see myself in an entire world. While I'm dreaming it all seems so real as I have no other point of reference. It's only after I wake up that I realize that the entire world I just experienced, including the other people I thought I was talking to, were really just a projection of my own consciousness. It all took place in my mind. What I thought was matter and other "consciousness beings" weren't that at all. How can I know that dreams aren't just an echo of a greater reality that we're experiencing while "awake"? Will I, at some point, awaken to an even greater ultimate reality?