Agreed! This is a beautiful piece.
I could imagine that the song would also work well with vocals and a singer.
Also agreed. I wouldn't sacrifice the instrumental, mind you, because I love it as is. But the pop songwriter in me could totally hear a vocal on this.
To that end, in my early songwriting days, I had a songwriting partner, and the way we worked was I'd make "tracks" (80s dance music, mostly) and he would see what inspired him. (You know, because my tracks were so inspiring!

) Then we would bang out songs from there.
I could see doing the same thing here. If you could find some soft-voice singer collaborator to send tracks like this to, I'll bet they'd come up with really great stuff. The trick, of course, is finding such a collaborator, but I'll bet lots of singers who aren't "songwriters" do have the ability, as well as the desire. They just don't have that collaborator on their end, either.
Just a thought, and in now way do I want to detract from the fact that this piece is really great as is.