Clicking on the following button in the Vintage Uninstall tab
or this button on new OS2 installations where a Vintage install is present
Will completely remove the old section code from the theme along with all existing Slidey Bar configuration.
This is not recoverable and any new install will require fresh setup
For Upgrades to OS2 - the legacy setup is incompatible with the new version due to the new architecture and its recommended to full remove it to prevent any potential conflicts.