We like to use Esris Basemaps in our 3D Webscenes, which is only possible in global webscenes, which unfotunatly dont support "close to" or below ground Navigation and dont support to limit scene extent like in local webscenes.
In local webscenes basemaps are only supported with WebMercator projection, which cause huge, inaccaptable height distortion, eg. towers appear squeezed, much smaler in height but wider than reality.
So we like to use the advantages of a local 3d Webscene in our (well known) projektion system AND use esris Basemaps. So please make basemaps available for local webscenes in other coordinate systems, like it works in ArcisPro. At least for all the well known projection systems like ETRS89/ UTM etc.