Does a supported language guarantee accurate translation in smart glasses?
No. A supported language means the feature offers that language under its documented conditions. It does not guarantee that it will understand every accent, proper name, technical term or conversation with people speaking over each other. Availability can also depend on translation direction, region and downloaded resources.
Test the vocabulary that carries the meaning
Everyday phrases can work while the terms you need for a particular conversation fail. Names, quantities and negation deserve special attention because a fluent sentence can still get those details wrong. Test both directions if each person will speak a different language.
For a hypothetical product discussion, include phrases such as “We need fifteen units, not fifty” and an invented product name. Ask a competent speaker to judge whether the meaning survived. Treat a language list as a starting point for that test, rather than its result.