So it dawned on me a few days ago that Vulcans probably have no need for universal translators. I imagine they can mine brains that function in an unknown language for context, emotion, meaning. In fact yeah, I've seen Spock do this by touch on multiple occasions. Once he remotely implanted a suggestion in some savage lady. Now, who's to say they cannot function like Miss Martian in Young Justice, as telepathic hubs for (in this case) verbal communication between races alien to one another?
This is what I imagine it working like. This could be seamlessly integrated into the established canon(s). Basically, every ship, space station, major planetary hub of interspecies contact has one Vulcan per perhaps a hundred people, pulling a full day shift while meditating and allowing his or her mind to become a psychic freeway, all the while managing not to get swept up by all the emotions; perhaps even somehow remaining unaware of the content of everyone's exchanges. Or maybe this is a skill vital only to first contact, until the vocab can be loaded into everyone's UTs.
Either way, this could become the reason the Federation is the only truly tolerant government in the galaxy. All other species aim to exterminate and/or assimilate other cultures. 'Cause learning a new language is so! much! harder!