This stems from different HDR workflows that I know.
In Photoshop for example, you can merge multiple images to a single HDR file. As far as I remember, when you go for a 16-bit file you also pick one of the processes that makes everything look funky and colorful, i.e., tone mapping. In contrast to that, when you choose 32-bit, it just merges the images into a 32-bit file.
To me, that 32-bit workflow is what HDR is all about: creating one image that has a higher dynamic range. Getting that back into 8-bit files for display is a different story.
Why is there no such workflow available for 16-bit files? Is that just the way Photoshop is?
If there was an option to merge to 16-bit HDR, would that be the better choice? (Given the possibly smaller file size) When/why should one bit depth be chosen over the other?