Please create a function in ArcGIS Online MapViewer to directly enables a WebMap for Offline Use in Collector for ArcGIS.
I know each Layer-Settings should be set correctly, respectively "enabled for offline use". But imagine having a webmap with 20 different layers it would be so much easier to just click "Enable WebMap for Offline use".
I could also imagine just to add functionality that checks for Offline use and returns the specific Layer, whose settings block the offline use of the WebMap in Collector for ArcGIS. This way we wouldn't have to check the settings of each Layer within the WebMap whether its settings allow the offline use.
This would be a massive improvement in user-friendliness for the offline use of WebMaps in Collector for ArcGIS.