When publishing multilayer map or feature servics they generate a single item in Portal. This improves the user experience by essentially createing "grouped" layers. However, this impacts of the discoverability of the layers winthin these services. There is the option to manually turn individual feature layers into items (FAQ—ArcGIS Online Help | Documentation) but it is cumbersome. I would like to see an option at the point of publishing to turn these layers into items. This would be on a per layer basis with the option to select all.