Do people actually use Fluent? When I showed it to some professional translators, the reaction was along the lines of: “Hmm, interesting, but does it fit into my existing [roughly speaking XLIFF] tooling? No? Then no.” More generally, a technical translator’s flow is turning a table of strings into a table of strings with minimal distractions and the occasonal look at the reference; I’m not sure Fluent—however nice it looks—facilitates that.