A small amount of non-English people will know what porter means. I understand some people such as
@baconcat think that everyone is instilled with the
curse gift of English with their first fart, but just to showcase language barriers: the Dutch 'portier' only refers to someone in charge of entrance doors, not someone who carries your luggage, while the latter is the main definition for the English 'porter'. Its Dutch Wikipedia page even compares the word to the English 'gatekeeper', because that's what the job entails. Someone who carries your shit for you is literally called the Dutch word for carrier in Dutch, because that's what nouns are for. Now imagine how languages that
didn't borrow this word from Latin via Old French might differ.
That said, I don't think a job title is particularly impactful in any manga (if it's not a plain mistranslation), because you only need one text bubble to explain what the job entails. However, the original
"It … invokes the idea of teleportation" argument is a poor one, because carrier invokes the idea of 'someone who carries items' to many more people and most importantly: it leaves 0 ambiguity. That makes it an objectively better translation.
While MangaDex currently does not seem to have it listed at all,
Manga Updates does show it as an alternate title, for the porter fanatics among us: