Currently in Collector for ArcGIS, when you take a map offline, you are able to sideload basemap files (TPK, VTPK, etc.) using iTunes and use those basemaps with your offline map. It would be very beneficial to have this same feature in Explorer and for it to work with MMPKs. I work for a utility and we currently use Explorer to provide a facility map in the form of an MMPK for our territory, which encompasses the entire state. We use Collector for inspections and data collection via managed offline areas. In Collector, we have sideloaded TPK files of NAIP aerial imagery split by county for offline use. This is very useful for our field workers, as my state has many areas with little to no cellphone coverage so we use offline solutions for everything. Therefore, being able to provide this same function in Explorer for our mobile map package facility map would be very beneficial to us.