

I’m wondering whether
Europeansthe other 96% of humanity
There, FTFY.
And yes, the other 96% of humanity would very much like to see Imperial measurements die.
Hell, as a Canadian born after 1970, I wouldn’t understand almost all Imperial measurements even if they smacked me clear in the forehead. About the most I have ever used are inches, feet, and pounds, and only because they’ve hung on in tightly-linked-to-America blue-collar industries and (until about a decade ago) grocery stores. I would have zero clue how much a cup or a Florida Ounce is.

In this context I see a baseline as a language that
And for some countries, there would be several that could fit both criteria. Switzerland would likely have French, German and Italian meeting all thresholds, allowing all three to be baseline languages.
Unfortunately, French does not meet the minimum-used criteria for Canada, as only 18% of citizens can speak it with any great skill. However, the geographical concentration criteria would likely overrule the usage criteria (via Québec), thereby allowing it to remain a baseline language.
Secondary languages would have similar criteria, only relaxed somewhat.