With a well calibrated display and a pair of good eyes I went through all 65 levels of brightness (I usually use 40% or so) my laptop has available whilst looking at ¹. All parts of page were very readable at all levels other than no backlight and two levels above no backlight.
Fahrenheit is not easily addable given current realisation of functionality and, if I recall correctly, somewhere in source code there’s a comment in which author explicitly states he doesn’t support units which don’t linearly correspond to SI-based unit.
Exactly, which makes me wonder why the library can support Celsius but not Fahrenheit.
To say it in more detail: To transform between Celsius and Kelvin, you just translate. (That operation is supported in Dimensional.)
To transform between Fahrenheit and Celsius or Fahrenheit and Kelvin, you translate and scale.
We know that Dimensional can scale, because it supports things like miles to kilometers. We know it can translate, because it supports Celsius to Fahrenheit. Is it the combination of scaling and transforming that makes Fahrenheit impossible?
Some cities are better for this than others. Unfortunately many of them were built in the automotive boom where futurists predicted compact roads would dominate the ground level and everyone else would walk underground or in sky bridges between buildings.
Maybe we'll grow into a reasonable solution for pedestrian traffic in cities, but the population distribution outside of those cities absolutely necessitate a car to get around.
The Russian counter-example may be valid. Offhand I would wonder how much of that 17 million km² is actually habitable, but even halving that still puts it on roughly equal footing with USA. Having never visited Russia I have no idea how it compares with pedestrian traffic vs vehicular, except the craziness I see on the dashcam videos that have been popping up everywhere lately.
Maybe we have a few things we could learn from them, but the point I was trying to make was that one 9.827 million km² country has to be architected rather differently from one at 84,421 km².