Request for suggestions: Alternative use of TV mount

I am a laptop user that is eyeballing the feasibility of installing a laptop holder on an articulating arm, connected to the stock TV mount in my Kenworth T680.

The first thought that comes to mind is getting a 2"x10", drilling some screws into it through the default holes on the TV mount, the mount an arm onto the wood block, but the stock TV mount has a weight capacity of 22 lbs, so I'd rather pursue lightweight strategies.

There are plenty of clamp based mounts, but they all appear to designed to be clamped onto horizontal surfaces like tables, not vertical, and rotating 90 degrees runs a risk of the laptop mount being unusable.

Additionally, the top of the TV mount sits 21" above my mattress, while I'd like to have the laptop holder sit about 8" off the bed when in use, finding a wall mounted articulating arm that bends at a significant decline has been impossible for me so far. It should also be stated that the furthest point I'd need the laptop would be apx 36" from the TV mount on a horizontal plane. I'd also appreciate any clamping solutions to be attached on the top of the TV mount, to let gravity assist when I slam into potholes.

And to answer the question of "why": right now I pull out a bed bath and beyond breakfast in bed tray to leave my laptop on, I'd rather have something that isn't a production to start up every time I want to use it.

So yeah! If anyone has any suggestions of items to look at to solve my conundrum, I'd be appreciative.