Vi (and ed) are the only text editors required to be included in the POSIX spec. A base Unix (and most Linux) installs will have some version of vi or vim installed by default.
If I'm working on someone else's box this pretty much guarantees I can edit files with my basic vi knowledge without having to install a different editor.
I have access to a SMD oven (just a toaster oven with a fancy controller.) Manually applied solder paste, placed the parts and they flowed just fine. Same process with a hot air gun should work but will be a little more finicky.
I bought one of the kits and assembled it myself (although it looks like kits aren't currently for sale.) The only hiccup I had during assembly is the random board profile I found in the Arduino IDE had the chip layout reversed which took me a few minutes to figure out based on the source.
This might not be what you're looking for, but interactive sorting can be fun. An old professor ran this with 5th graders where each help a number and they would physically move according to the sorting algorithm. Show's the number of compares and moves in a visceral way and demonstrates the difference between bubble / quick sort in an approachable way.
If I'm working on someone else's box this pretty much guarantees I can edit files with my basic vi knowledge without having to install a different editor.