Don't know what Bun does though.

If you want to use TS stripping for your own project the typescript ecosystem makes it very easy to avoid using the wrong features. Just set erasableSyntaxOnly and verbatimModuleSyntax to true in your tsconfig.json and you will be warned when you're doing something node would not be able to handle. These days I find more code is being written to be stripping friendly than not, the incompatible stuff is of little importance besides enum for which you could resort to an as const object or a string union. I consider the presence of such things a smell, the TS dev team considers things like enums to have been a mistake, the goal of TS is to remain minimally divergent with JS outside of the type annotations.