Are there any updates or new features in terms of HDR functionality or performance?
Yes, there are some quality improvements and halo reduction options.
We improved the algorithm to reduce halos and added a Edge Smoothness check box to suppressed the sharpeness of the edge to allow higher boost of the texture or detail of the image.
We've also added some new HDR presets to give some good commonly sought after HDR effects.
Any improvement to the registration algorithm?
For HDR, changes are to just what we've mentioned here so far.