There are several autocompleters, and the “Near Autocompleter” is the one that helps users find a location page. Members often create links leading directly to location pages, too. In either case, having a ‘list of locations’ is needed first.
to utilize the exact same google autosuggest input field that is used in the “add a listing”
This would not use a list of predefined locations, and would seem to workaround most of the GD Location functionality. It is not possible for us to carry out that kind of customization here in support, but the developers have been alerted to the idea and will consider it for future versions.
Anything is possible with code, and GD Experts are to be found here: https://geodirectoryexperts.com/
We will be taking a look at additional improvements once GDV2 is out: https://wpgeodirectory.com/geodirectory-v2-final-roadmap/