PREVIOUSLY: YOU SAW THAT PLUMES ARE FICKLE BEASTS
Okay, my 3D models are not quite done yet. This stuff takes a lot of time, and if you know a thing or two about numerical methods you can see why moving into an entirely new dimension would up computation time by heaps.
Fine in the spirit of full disclosure I'm not even at the 'freak-out-about-computation-time' part because I'm still tirelessly debugging.
Moving into three dimensions provides a much more realistic view of flow! For example, when material pushed away from a ridge has the ability to move around a thermally buoyant plume there is not as substantial a deflection. Perhaps when I have better results I will describe this better and more quantitatively. Here are some of my preliminary results.
It's finally happening, still working out some issues with modeling a ridge in 3D. But look at that plume bend!