Text("/(capacity) people")

is translatable

From what I remember, that’s more or less how iOS translations works already https://medium.com/swift-india/localize-your-apps-to-support-multiple-languages-ios-localization-ac7b612dbc58

That one uses NSLocalizedString

Maybe it just finds the matching key by replacing whatever in

/()

with the correct specifies, which can be done by inferring its type?

Yep. VERY brittle and same as it's always worked. I never knew an iOS dev to like it since it lacks all safety.