Adjustable Book, DVD/BluRay, Game Case Stand

There's a Japanese book stand that I saw in a reel that uses these triangle shapes that lever up to allow books or DVD/BluRay/game cases to slot in and not fall over. When you pull the book out, the triangular piece should come back down.

This is model I put together that mimics that functionality, but can be printed on an A1 Mini and can expand infinitely using joining pins.

The printed version in the pictures was with Sunlu High Speed PLA Marble in Shadow Storm. No extra parts required.