When using runtime apps or Collector to collect data in an offline geodatbase we currently have to choose between not being able to add attachmetns, or having to download all the existing attachments. For projects with a large photo collection component the inclusion of previously added attachments can quickly make the runtime database too large to download.
Ideally the ArcGIS Server feature servcie endpoint should let us specify support for new attachments as well as if we want to download exisiting attachmets when creating a runtime geodatabse.