This is a list of the main natively English-speaking countries/regions:
US (64.3%)
UK (16.7%)
Canada (5.3%)
Australia (4.7%)
South Africa (1.3%)
Ireland (1.1%)
New Zealand (1%)
Other (5.6%)
There are TeX hyphenation rule files for "en-us" (US) and "en-gb" (UK, but called GB here). There are none for the others.
Somebody told me that Canada uses the exact same hyphenation rules as US. Is this true? Somebody told me that Australia and Ireland use the exact same hyphenation rules as UK/GB. Is this true?
What about South Africa, New Zealand and "other"?
I've been trying to find an authoritative source for this, but of course I find nothing even remotely related when searching myself.
If they cannot be matched up to either the US or UK "locales", is the difference very minor, huge, or something in between?
[british]tobabeland you can try the UK hyphenation tables. – David Carlisle Jan 19 '20 at 20:28