There is one place where TAU do have a leg up is woodworking. This is because the divisions strongly favor halves and humans are strangely good at visually dividing things into two equal parts. Most woodworkers will agree it is easier to work in TAU (or in the UK and Commonwealth "Imperial").

My woodworking was building loudspeaker enclosures. The maths gives the box volume in litres, so the dimensions come out in millimetres.
Sheet sizes were always 8' x 4', which became 2440mm x 1220mm. Then recently, and very quietly, they changed to 2400mm x 1200mm, so if you cut 4' off the sheet you thought was 8' x4', you haven't got 4' left!

 

I ... knew people that could work in feet, yards, inches in their head, tell you almost instantly how many inches were in 9 yards, 2 feet, 7 inches.

that tells that such people do exist but they are selected few.
compare that with metric system where everyone can tell without any delay how many millimeter, centimeter, decimeter or kilometer is in 189.47m

 

that tells that such people do exist but they are selected few.
compare that with metric system where everyone can tell without any delay how many millimeter, centimeter, decimeter or kilometer is in 189.47m

Given that I increasingly encounter people that can't add 5 and 7 without using their fingers and speaking out loud (and still get it wrong) or that can't figure out that, 24 cents plus 1 penny is equivalent to a quarter, I wouldn't be to sure that "everyone" can tell you all of those things, despite the odds being stacked in their favor. In fact, just recently, I've been working with a sophomore computer science major that struggles to multiply and divide integer values by ten. It really has gotten this bad (and will only get worse).

 

All my formative years were Degrees F and later years involved living in a few other countries beyond the US. This made me comfortable using either. While I prefer F I am also fine with C. While living in Italy my daughter was 2, 3, and 4 years old and she just naturally learned English and Italian. Here in the US we use F, my evening news and weather uses F so F it is.

Ron

 

Did you ever load bulk grain? Were the units used Bushels (a volume unit) and had to convert to MT?
Similarly to loading Barrels of crude oil, again a volume unit, but with different weights depending on the crude type.

For almost 7 years, as a Ch. Officer in bulk carriers, loading mostly grain / by products but also coal or fertilizers. The first two mainly from Argentina but also Uruguay or Brazil.

Freight is charged by weight: USD/MT.

To estimate the intake of a vessel you use the SF (stowage factor) given in cuft/LT in the past and in m3/MT nowadays. It depends of what grain and the year of harvest and humidity.

In voyage, dew point and temperature, regarding ventilation comes into play too.

In tankers (I was in that type also) whether crude, subproducts, chemicals, oils or God knows what, you ask in advance, tonnage, density and temperature.

Myself never been exposed to bushels/barrels.

In LPG carriers (been there too!) you add another component to the mix: pressure-temperature.

Reefers (not my game) use volume, temperatures and with certain specific cargoes (fruits/vegetables) they take care of CO2 tenor once stowed and hatch covers battened down.

Complex life with units out there...