When you make any changes, the app is taking the latest score as the current one, regardless of device it was entered at, or if scores were incomplete.
When you sync data between devices the screen where you accept scores show you number of scores that changed if you pay attention. So, you can review them after the sync.
You can see the history of edits on review screen. Also the number of edits shown next to the shooter names in red boxes.
Additionally you can filter competitor list for incomplete scores or for number of edits. See more details at Search and filtering options in PractiScore apps