Question: It feels like workaround, but isn’t there a more convenient
way to handle such issues? I just pretend there will be more and more
untransformed packages outside in the near future (following this
discussion) and do we always have to manually put the package names
for it in webpacks’ exclude rule??
You can use modules like are-you-es5 to automatically create an exception list or test: https://www.npmjs.com/package/are-you-es5
Also things like eslint-plugin-compat could potentially warn you of issues if pointed at your node_modules: https://www.npmjs.com/package/eslint-plugin-compat
It’s not perfect though. I think in production settings in general you should just be cognizant of the packages you add before adding them or have some automated tests that would catch browser errors if IE11 is critical for your project.
I know it is not always possible but I would strongly suggest pushing IE11 and below to some lower tier support. It is very difficult to still maintain IE11 and below while using modern JS.