Setting LightmapEditorSettings "Mode" via script

I have been writing a script to read set light bake settings info from a single location that allows our artists to source a particular light setup based on the name of the level. Before you ask - yes there is the awesome Beast Lightmap settings file - but using this still means managing multiple lightmap settings files - just wanted to do this from one JSON file. I also store a bunch of info about what to ignore for the level type, what lights to instanciate etc (so far its pretty handy)

Everything works fine but I can't seem to find a property for setting the 'Mode' in LightmapEditorSettings. This would allow me to force "Single" instead of the default Dual. The reason this is semi-important is that when you start a new level the lightmap settings will default back to Dual and given some of the guys are new to Unity (and I regularly forget) we are forgetting to check this part when we go to light... tends to bloat the download size with all those extra maps.

Any thoughts? LightmapEditorSettings.mode would be logical - but its not a thing :) There is a runtime module for LightmapMode but this is to set (at runtime) how the scene will use provided lightmaps and nothing to do with the actual bake.

Cheers in advance, Damon.