The idea of a language server also being some other kind of server is almost fiendishly clever to me and I'm shocked I hadn't seen other people play with this before. Definitely can think of applications to game programming -- a sufficiently dedicated engine team could fork their language's LS and allow you to e.g. integrate the map editor's feedback into the source code. I know hot-reloading is considered super valuable in games, but this is almost the dual of that idea. So clever!