I can hardly think of a way to do it less error prone than with thoroughly considered spreadsheet formulas.
However, just for fun I wrote user code for the conversion of reasonable values to representations with arbitrary subdivisions. Of course, I did this in a generalyzing way, and not yust for “imperial” length values. My playground was mainly the funny Pound, Shilling, Peny currency.
Of course I would also prefer to offer retirement to time representations which are based on about 3000 years old (mis?) conceptions.
We would easily learn to do it with cd (centi-day, not candela) e.g.
The scientific s (second) should remain unchanged.
Even the USA joined the metre convention more than 100 years ago, and GB reformed their currency suibdivision to decimal, and introduced ISO paper sizes.
See attachment:
disask_128742_xFormat_justforfun.ods (38.5 KB)