When you purchase SyncTime, you can uninstall SyncTime Lite from the Launchpad or by manually dragging it from the Applications folder to the bin.
The sync item settings created in SyncTime Lite will be used automatically by SyncTime.
Keep in mind that the only limitation of SyncTime Lite is that when the app is closed and opened again, it will start over with an empty list of sync items. At that point, it won’t be possible to use the previous sync items in SyncTime anymore. If you want to keep the sync items created in SyncTime Lite, close SyncTime Lite, uninstall it, and use SyncTime from that moment onward.
If you installed any scripts to be executed when some sync completes, you will have to install them again in SyncTime, since macOS doesn’t allow sharing scripts between apps.