Comment 8 for bug 1850275

Some aspects sound quite problematic to me.

What should be the decimal separator, the first day of the week, the currency etc. (let alone a few less important ones e.g. phone prefix, postal format)?

To second Andreas's point, what are the desired use cases to which setting separate LC_whatever variables isn't sufficient currently? Would an en_EU then be definitely sufficient for all these kinds of requests? Wouldn't something else, e.g. improving the way users could generate their own locales (tools, docs) a better solution?

If en_EU is added then shouldn't there be a fr_EU, de_EU etc., for ... for which languages exactly?