I'd like to try this kind of setup (coding from a lounge chair with just a keyboard tray & trackball, yay!), "dumb monitor" would be sufficient - but since switching to high-DPI displays in 2016 I really need this to be 4K.
I did this with nreal air glasses (now xreal air), specifically for coding. Most uses cases for these type of glasses is around media consumption, so I was taking a bit of a leap when doing it for coding/heavy text usage.
There are two modes. One is fixed so that the virtual monitor stays in one spot on the lenses. The single virtual monitor stays directly in front of you. The other is floating, which basically keeps the virtual monitor in one spot and you can turn your head to look away. This mode also lets you set up 3 virtual monitors side by side so you can turn to look at them. It uses head tracking to basically shift the image in the opposite direction you turn your head.
In both cases, the screen does move, and this is super relevant when looking at text and down at status bars. The fixed one is better because it moves relative to your head, but both cases have some amount of jitter. I found the best case coding scenario is the fixed monitor (no head tracking), and being in a seat wth head rest and you can press your head back into it. This minimizes your head movement, which minimizes how much the text moves about. The downside is that we're used to looking up and down at the screen, so you want to set the monitor at a proper distance so you can look up and down with just your eyes. You really want to shrink the monitor to a size close to that of a laptop.
I ultimately ended up not liking the experience very much. No matter what, you're gonna end up with some amount of text movement. There is also a bit of light saturation bleed through (old CRT style). Putting the blackout blinders on helps a lot, but the projected nature remains an issue. Essentially only usable long term in a recliner or a car seat with headrest. Unlike the author, I am using a work provided laptop and I have that with me anyways. There was coolness to leaving the laptop in my backpack and just bringing the glasses up via wire - but to actually do anything, I need a keyboard. Which means taking along a Lenovo's thinkpoint trackpad keyboard (really great backpack keyboard); or pulling out the laptop.
The newer ones, like Xreal One from the article might be a better experience. A coworker had the air 2 pros and used them for travel. He said he didn't really notice the things I did, so maybe it was a improved experience even with that version. But he mostly worked in office documents and only occasional terminal work. When traveling and using the glasses, it was almost all "office docs", and only for short periods of time. For me - I am going to wait and be a slow adopter to move to a new version.