So, it's in a pretty standard form factor, of a thick & heavy tablet, but I suppose my daily driver otherwise counts as cyberdeck-ish.
This first picture shows the back, as it currently stands with its rough first design made of balsa wood & wood glue,
showing the RPi 5 w/ 16GB RAM in the center, also with an official RPi USB3 hub with case removed and coveree in kapton tape,
two AmpRipper 4000 battery managers at the sides of the Pi (one for the Pi 5 itself, one for the USB3 hub which also powers the monitor,
and two sets of four 3Ah LiPo batteries, connected in parallel (matched to the millivolt before joining each other, first two sets of one+one, then one set of two+two), for 12Ah per AmpRipper 4000.
Here are two older pictures of the front, though of course it hasn't changed. I'm using a WaveShare OLED 2560x1440 13.3" monitor, which can thankfully be powered with 5V 1.5A.
I went with a tablet kind of form factor, as opposed to a laptop kind of one, so that I could set the monitor in landscape or portrait mode. A tablet-like form factor also allows me to not have to bother with laptop hinges, which I'd otherwise been trying to figure out how I could make it work, especially if I wanted to maintain the ability to rotate the monitor. The best answer for me, at current time, is just to go simple instead.
Here's my Fediverse thread with more details and more photos of my progress to date.
The Pilet was mentioned above, and I'm indeed curious about how the design turns out! In particular, I want to see its schematic for getting 5V 5A from its batteries.