FFTRegistration in PI works very well for aligning lunar images, and the processing tools PI offers allow for excellent lunar image processing.
What's missing in my opinion is the video frame analysis to select the very best frames for alignment and stacking.
Here's an example from last night: stack of 30 x 0.003 second frames at full resolution with my ASI1600 at 1050 mm. Unfortunately the forum requires that attachments be smaller than 0.5 MB, so resolution is degraded here, but honestly PI is a GREAT tool for these images. Now we just need a way to extract and select frames from a video file.