Here is what I know. Since I had AMIA poster on it 3 months ago.
There is an article in JAMIA here https://academic.oup.com/jamia/article/25/5/614/4093028
There is reponse to it from LOINC team : here
LOINC standard has a column that says “example units”. They are not normative. Best if we could get the LOINC team to formally comment.
Data driven concensus on units is here: https://github.com/OHDSI/ohdsistudies (folder ThemisConcepts) (see file …-ABC.csv) (or other forum posts)