For a while I have been using the following babel preset for production bundles:

        ...
        "presets": [
          [
            "@babel/preset-env",
            {
              "targets": [
                "defaults",
                "maintained node versions"
              ]
            }
          ]
        ],
        ...

This configuration seems to be incompatible with microbundle as it generates errors such as unknown Statement of type "ForOfStatement" when the source contains for (... of ...) statements. Using "presets": ["@babel/preset-env"] without specifying targets works. However, I am concerned about the compatibility achieved by such "default" builds.

What is the proper way to use microbundle to build for both the browser and for node? What's the correct babel configuration to use? I am fine with having one build for the browser and another for Node, but how should one define package.json exports in that case?

I do realize microbundle probably does the correct thing by default, but I am a bit skeptical given the existence of the --target CLI flag, for which little documentation exists.