The link you're quoting, the one posted, is a second hand US report.
The primary company link is from a UK subsidiary of Mercedes-Benz and is (almost) fully metric (the fundemental units US weights are officially defined with respect to (for more than a century now)).
See: https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...
Earlier in the summer YASA achieved 550kW (738bhp) from a 13.1kg version of its new axial flux prototype motor, equating to an unofficial power density world record of 42kW/kg
Now latest testing of an even lighter 12.7kg version on a more powerful dynamometer has shattered this record, with a staggering 750kW (>1000bhp) short-term peak rating, resulting in a new unofficial power density record of 59kW/kg
> The link you're quoting, the one posted, is a second hand US report.
You can tell, because a proper Brit would have given it as 2 stone, not 28 pound.
That seems unlikely, a proper Brit would know that a stone is defined for body weight (14 avoirdupois pounds), Wool (14, 15, or 24 pounds depending on wool class), Wax (12 pounds), Sugar and spice (8 pounds), or for Beef and mutton (8 pounds).
( Of course Scottish Britains used 16 Scottish pounds for a Scottish stone ).
The point being that 'precious' metals used a different weight measure altogether .. (common lead often used a 12 pound stone).
Such a fun system.
Prior to the Revolution, in France alone there were allegedly 250 thousand various units in use! (All sorts of units, not just length.)
It didn't help that pre-Revolutionary France was a political Frankenstein stitched together from dozens of regions with completely different history (Celtic Brittany, Flemish Dunkirk, Germanic Alsace, Provencal South, Catalan Roussillon, Italian Nice) and thus very different local standards of everything, including measurements and law.
Unification of units removed a massive constraint on international trade and engineering. Except the US and Myanmar, of course... it is so frustrating to order anything from Myanmar e-shops, I must say. But Myanmar is at least promising to move on.
Nitpicking: Nice wasn't part of pre-Revolution France, it joined in the 19th century during the Italian unification.
Is that nicepicking, then?