I played with it a little and got it to export a lightmap or better to say several files...
But I am not sure how to use that afterwards...
The process is like that:
1.) Create a Chor, put some things into it and a light. For tests I would start with a simple object and one light.
2.) Right-Click on the Chor in the PWS and choose "Export > LightMaps".
3.) In the Export Lighting Maps-dialog you can choose a directory where to export to, if you want to export a polygon or a patch-model. (that is only necessary for polygones per patch-settings)
4.) Scale the Map... just use 100% for now and put a min- and max-size per patch/poly in which makes sense to you.
5.) Render-Method... I am not sure what that is... I think it is about that mapping style like for IBLs, but I am not sure.
6.) Map Intensity Scale is just how intense the lights should be, as far as I think.
7.) Choose if you want to have shadows in the map or not. (would only use that for static objects)
8.) And then choose the Fileformat you want and export it.
9.) Now for each object (in a folder with the name of the object) A:M will export for each patch/polygone a image file. That seems to work, since the files are reasonable looking. (you can easily test that, if you have a look at the ground-model-files...)
The problem is: I do not know what to do next with it... how to put it back on my models (without doing it by hand) or how to import that in another software or whatever...
I think it would need an Import-Lightmaps-Feature for the chor or the models and that would need to map the images to the different patches so that we could use for instance bakesurface to bake it and use it externally.
So what is needed there is an importer, which can assign the images as patch-images or something like that. I do not think, that is very hard to do, but I am just not sure about it...