I miss defaults for length (eg. Meter or US-units) and weight (Gram or kg).
You can find the UoM EDI X12 DE355 under https://www.disa.org/apps/workbook/X12_October_2012/de/355.htm or take this:
By the way: the default defined UoM's are not assigned to a UoM Type - mostly "time" (hour, dey, ...).
A good contribution can a 2pack (or CSV) creating the UoM defined in that page.
Closing as potential idea