Environments can only be imported as new, but some sort of “update” functionality, which imports an environment file into an existing environment, would sometimes be more helpful.
Otherwise one has to first delete the environment of the same name, and import it afterwards from file. If one forgets to delete an environment of the same name first, one ends up with multiple environments of the same name.
It could also be an opt-in feature of ticking “Merge existing” at the import function, and extended over all imports.