This design was remixed from a model created by mvgordon.

I removed the dock mounting as I have this placed in the tray, added another upright for extra rigidty. Made it a single piece so no screws required. I then created a snap-on stopper for the laptop, so that I can slide the laptop in with ease, until it hits the stopper and know that it's in a balanced position.

My design is not as neatly polished as the original but it gets the job done and is out of sight.

Unfortunately the stopper was an afterthought, so it's a separate piece. This does have a benefit in that you can place it at a height on the hanger that meets your preference, to perhaps avoid ports that you need access to. It's possible this could be incorporated into the main piece if it fits build plate restrictions. I welcome you to create this as a print profile.

The screw holes at the top on the main bracket, may require some minor up-sizing, I used a deburring tool for this, the screws were just a tad too snug for easy installation. Because it was so close, I don't want to change the hole size in case of tolerance variations.

This mount fits a laptop that is 31x21x2(cm) with room to spare. The STL is included if you would like to adjust sizing.

I used the Strength profile but reduced Wall count from 6 to 3 to reduce filament usage. With 25% infill, Gyroid. The result is very sturdy. Supports are needed for the overhanging second upright. I used Tree (auto).

I have no idea if there is a less wasteful way to achieve this, I'm pretty new to designing and printing. But I did try to balance print time, waste and strength, and am pleased with the result.

Hope it's of use to somebody else!