. . . it seems weird that these are reported with a lowercase 'k' but 'M' and so on remain uppercase.

For SI units, the abbreviations are defined, so a lowercase k for kilo and uppercase M for mega is correct. Lower case m is milli, c is centi, d is deci. Uppercase G is giga, T is tera and so on.

https://en.wikipedia.org/wiki/International_System_of_Units#...