I have had standing desks for years. In fact, I recently posted a photo I found of the standing desk I had at our Lake City house. When we moved onto the boat I was bummed that there was no area that was both compact and out of the way enough for a standing desk. A couple weeks ago I accidentally ran across the solution!
What I have set up now is a monitor mount with a tray on the arm instead of a monitor. It has been working great! The only major issue I have run across is the monitor height. Because I am using the built in laptop monitor I am looking down, which hurts the upper back after a while. Thinking now about getting a small external monitor to mount similarly above the laptop.