> I do prefer Fahrenheit for HVAC (and weather) because it’s higher resolution and has reasonable values at human scales.

So you are one of those, lol. There is nothing "less human" about 25 C than say 72 F. Nothing, it just happen to be the scale you are used to.Both are arbitrary.

> Fahrenheit for HVAC (and weather) because it’s higher resolution

99.99% of thermostats and thermometer in C had at least 1 decimal place. At usual "human temperatures" the difference in resolution between the scales is less than 2X, so even assuming only integer values, I am willing to bet against you in a double blind test that you cannot differentiate 68F vs 69F in an statistical significant way.

> I find it easier to say that’s three eighths than 9mm

Just because you are used to. Fractions are more complicated than integers, every elementary school program knows it.

So to summarize, the problem is not with the magnitude of the units which is arbitrary (a degree F and inches are not more human, logical or normal that a degree C or cm)the problem is with the convoluted way of the imperial system for multiples and submultiples of the base unit.

Interesting comment on Fahrenheit, as I would say it has too much resolution for day to day use. A nice sunny day is in "the low 70s". A cold winter day is in "the high 20s". There is too much precision in the units to give an exact numeric value, so we round it to low/mid/high. That implies that the general unit we should be using is somewhere around 3 times larger than Fahrenheit degrees, because that is the size of the unit we use in speech anyways.