Are there any plans of making JS interop more compatible between Kotlin/JS and Kotlin/Wasm ? It shouldn't be hard or backward incompatible to introduce

JsAny

and add it to all built-in external declarations?

No specific plan for now, but probably we’ll continue tuning interop on Kotlin/Wasm side

Why would it?

Changing upperbound or types will change signature used for linking, so compiler will unable to link references from old klibs with a new library with Browser APIs

Oh, I see. I was thinking about source compatibility, not binary compatibility.