When using a map tile package stored on the device you currently select the offline area by zooming in/out to specify an area within a square, it would be much better to instead use a polygon layer such as parish boundary to choose the area or areas for download. So choosing an individual parish or multiple parishes. This would give greater control over the amount of assets downloaded which is especially helpful when working with very large volumes of asset.
Moderator's note: This idea has been marked as a duplicate of Collector - Work Area. Please consider voting on this idea and leaving a comment to share your user story.