Backdrops

Backdrops tab allows you to configure which layers will be available in backdrops menu.

The setting show above will result in following Backdrops menu configuration.

With the Use dropdown after the following number of backdrop buttons option, it is possible to collapse backdrops into a dropdown list.

Backdrops are mutually exclusive layers or groups of layers that you can switch on or off with a click of a button.

This feature will most likely appeal to Aurora users because it will allow them to change the "background" of the map that they are browsing – be it OS MasterMap, 10k raster or some historic imagery of the area. In that context it is pretty useless for Earthlight users – we all use OS MasterMap at large scale and either OS VectorMap District or some 10k or 50k raster imagery at small scale. And we configure the visibility of these in such a way, that different backdrop layers do not overlap.
When thinking about a way to utilize this feature in Earthlight I believe the term "mutually exclusive" is the most important descriptor. Below is a Backdrop set up of a Land Charges Map with all Planning Application layers from different years easily accessible.