Great question. I don't think that it's documented - yet
Local client settings are saved at %localappdata%\Check Point\SmartConsole\R80.10\UserSettings
For portable SmartConsole, this is stored inside the portable folder at the "Output" sub-folder.
This means you can delete them to clear previously entered IP addresses, last viewed page, rulebase column display settings and more.
You can also keep them between uninstall and install of SmartConsole, although this is only supported if the build of SmartConsole is the same. Build == the value that you see when entering the top-left menu --> About SmartConsole.
Importing local setting files between 2 different builds of SmartConsole is not officially supported and could cause unexpected results such as UI crashes.