The language thing is something that I think about a lot when I read isekais. Like how it works and why some things translate and others don't. Not many stories actually address in any detail, which is understandable, but I feel like it would be an interesting idea for a side story or bonus chapter.
I need to know, does the translation magic work for songs? Do the lyrics get translated? Does it preserve the rhyme and meter? What about metaphors and idioms? Do they get translated literally or converted into a local equivalent? Somebody tell me I'm not the only one that thinks about this stuff!