We do not have a smart search plugin. Smart search works by indexing data then searching the indexed data. We're not able to apply our many access and privacy checks for profile data to the searching like we can with a live search. This would basically cause data breaches.

You need to use a userlist or use the legacy search component (assuming it still works on J5) with CB Search Bot. We'll be reviewing trying to support some sort of limited basic smart search integration in a future release, but we've to be careful due to the privacy issues.

We don't have any integrations with that component and have no plans for one at this time. So whatever integration included in that component is not provided by or evaluated by us. Unless individual profile access permissions and individual field per-profile access permissions are checked it could result in a data breach so you should be careful with what information you allow it to display.

Basically our plans for a smart search plugin is to allow index and allow searching explicitly public information. All private data will be excluded. So for some sites this might mean only searching by name and username and that's it. I don't know when this will be available though.

Should I uninstall smart search component and replace it fully with this one ?

That's entirely up to you.