I'll chat with you in English.

名無しさん＠英語勉強中

Part 3

Now, in conclusion, my question is, does "non-Japanese" in such
contexts still sound un-idiomatic? What about "non-Japanese students,
non-Japanese tourists, non-Japanese visitors, non-Japanese workers,"
and so on?

And what about "workers, products, etc. from outside Japan"?
This phrase "outside Japan" cannot be rejected altogether because
some Japanese companies do request us translators to use although
it may sound a bit funny. If you're in Japan, then the phrase
"overseas" naturally refers to "somewhere outside Japan." But what if
it happens to be in Tanzania or the Netherlands? In that case,
the phrase "overseas" is understood to mean "outside Tanzania or
the Netherlands." But the author of the document in Japanese assumes
that the phrase "海外" is understood as "outside Japan." In that case,
I am obliged to use the phrase "outside Japan" even though it may
sound a bit un-idiomatic in many contexts.

(End of my three-part post)