Thanks James, for the comments.
I wonder where the softness you’re seeing comes from; maybe it’s the result of slight camera movement between frames?
I don’t think it’s out of focus.
What’s funny to me is that, upon examination, the softness, which is present in the .DNG file too, looks as though it comes from a denoiser. I didn’t use one, though. Maybe that’s just a by-product of HDR?