This is going to bring most Americans to a grinding halt since we didn't go by metric system - that was taught secondary as an aside so most of us feel like 3rd graders again when we encounter it, right before summarily dismissing it in favor of the good old "Murican way.
bit is not metric at all! Apart from it never being defined not even on the tipping bot website where I saw it being used most, people hugely disagree on what it means and it totally confuses people.
mɃ and uɃ or µɃ are "metric-ish" as they are compositions of a base unit Ƀ/BTC/Bitcoin/
BTC (we all know) and a multiplier out of the well known set of nano (the smallest that would make sense for Bitcoin denominations), micro (µ/u to distinguish from milli that also starts with m), milli, kilo, Mega, Giga, Tera (and as Bitcoiners we increasingly get used to Peta-hashes/s as well as Exa later this year … and eventually next year Zetta
)