Hi Demostenes,
Thanks for the question. This is something I've been working towards, but it's not fully implemented yet. Generating flow maps is working, although there's no nice UI, and it probably needs some performance optimisations. There is also a prototype script function for using these flow maps as masks to bake a land type (e.g. erosion debris) onto the attributes map, although this too lacks a user interface. Just now I bashed together a very rough script to test these elements, the results of which are shown below, where I've used the flow map to overlay the 'mud' land type:
Having run this test, it's now quite obvious that I need to better integrate this into the core L3DT workflow, so that this masking can be more automated and more respectful of the other aspects of the terrain. For example, in the above image the mud land type was applied over lakes, sea, and rocks, which isn't right. It needs much better smoothing / blending.
I'll post back here when I've got something ready for testing, but please don't hold your breath: there is much to be done first.
Best regards,
Aaron.