Autodesk Civil 3D has a dialog to select which styles the user wants to import from a file to the active drawing. (see the attached image)

A checkbox next to each style.

In case the active drawing already has the same style (same name but different properties), you can choose if you don´t want to add that style or overwrite the existing style. (maybe a third option would be create a copy with a suffix..)

In MicroStation in the Element Templates dialog, there is Import and Export to XML file but the user must edit the XML file if he does not want a particular Element Template.

It would be interesting if when we select Import or Export then opens an intermediate dialog to choose which elements templates the user wants to export. And the same to import.