I haven't; I haven't tried Flow either which looked promising.

For kicks I tried the online Elm demo. Offhand it doesn't seem like Elm highlights errors inline(?). The syntax also looks a little foreign, whereas TS generally still looks like JS with a few exceptions.

I imagine Elm/Flow both have this, but another thing I like that TS does in VSCode at least with a watching task is collecting errors project-wide in a "problems" window.