Any way to download maps rendered by cycles nodes? I understand that this is probably completely impossible, but the chance that it is possible merits the question. Disregarding camera-specific nodes, such as fresnel, take for instance the pointiness node, which is entirely geometry based. Can I extract a pointiness map from an unwrapped mesh? This might sound uphelpful, because you could get these simple maps from handplane or xnormal, but what about very complicated setups, that are still completely geometry?

If it is really "No", I will accept that as an answer.
Maybe I'm not understanding your question, but in general you can bake whatever kind of map you want by feeding the attribute into a color input.  Using an emission shader and baking the emission makes things easy.  Uh, I think as with @Danyl Bekhoucha's answer here you should multiply the gamma by 2.2 so that the color is treated as non-color data when it is displayed (i.e. blender is going to gamma-correct it, so you need to un-gamma correct it manually).  Apologies in advance if I've gotten that confused somehow.



You may wish to edit your gradients with a color ramp or whatever, it's all configurable and depends on how you plan to use the data.