I thought I'd verify for others who arrive at this thread that baking out the image as EXR in Transfer Maps works to get out a 32 bit Displacement map. For me, the height was stored in the alpha channel while rgb is saved out as black. I also had the Rendering preferences set to "32-bit floating point (HDR)" as suggested…
It's been a while since I used it, but I think it's under Windows > Setting/Preference > Preference > Rendering > 32bit? Also, I think the TIF format for Maya is automatically 32 bit? If not, I know that you can use the custom Material to render, if you tell it to use a Displacement shader, although I'm not sure how to…