I am also quite irritated by the fact that many TTS fail to state what language (and probably even dialect) they support. Actually to support a really good workflow for many Europeans (and probably also the rest of the world) one would actually need a multi language models that also support the use foreign words within one's own language. I am using a local notification reader on my smartphone (with SherpaTTS) and the mix of notification language as well as languages embedded in each other makes the experience rather funny at times.