Basemap picker configuration

Hi. The basemap picker works well and it's great to be able to add scale dependant reference layers, however, it would be nice to have more flexibility for basemap configs. As it stands, one must select layers/services from the portal. I'm running into the following issue: I'd like to add the Nearmap tile service, but there is no way to save that service as an item in our portal. The tile service can be added to a webmap though. 

So, idea one, is to allow webmaps as valid basemap items. I suspect this would be useful for other use cases as well.

Idea two, is to allow a service URL in addition to items from the portal.

Thanks