How are libraries doing this and how well is it working?

Most systems that even claim to have authority control simply allow a
controlled keyword list. But this does nothing for the see and see also
references that are essential for many use cases (people known by many
names, entities that change names, merge or whatever over time, etc).

The two most obvious solutions to me are to write an app that provides this
information interactively as the query is typed (requires access to the
search box) or to have a record that serves as a disambiguation page (might
not be noticed by the user for a variety of reasons). Are there other
options, and what do you recommend?