I use a gooseneck holder for Switch playing in bed, but this is intriguing OP. If more people try it and report it's comfortable I might jump in.
One of the things that bother me about the gooseneck holder is that it's not very easy to quickly take it off or move it out of the way. Can't leave it hovering over my bed for long if I'm not playing, it gets in the way. And I get lazy to install and uninstall it for short play sessions. I was just thinking yesterday that I would like a holder that had like a swivel function so I could easily swing it away from the bed when done playing or taking a break. This visor could solve that issue.
9 inches might be a bit too close for my preference though. I might like the screen to be an inch or two farther. Need to take measurement of my handheld and gooseneck playing distance to check.