Shaggy man. I like your design. Good idea on the self tapping screws to tighten. Great idea on the wire material as well they should have a very long life. Also agree that 3*3 holes are best. Honestly man wanna trade haha just kidding of course but if I needed to build a screen and didnt have meterial laying around that would work. Yours is what I would build.
Edit. Except I’d put mine on ratchets to raise and lower. Only change.