Best practice definitions for derived units (acceleratios, jerks, etc.)

[dgoeries]

Going through the standard definitions in the default_en.txt file, would it be allowed (possible) to define best practice definitions for accelerations, jerks, etc. (https://en.wikipedia.org/wiki/SI_derived_unit)

• meter_per_second_squared
• meter_per_second_cubed
• ...

for the unit registry. Same for radians and there could be way more :-). I was wondering, as a standard definition typically ensures upstream testing and support if they can be added. I could prepare PR's.