When I tried to do 652 the images were 6000x4000. Today I batched 100 images, resized to 3000x2000 and auto aligned. It took about 35 minutes. The results were terrible. My computer is a iMac Pro 27" 2017. 3.2GHz Intel Xeon W, 32GB of RAM, Radeon Pro Vegas 56 8GB. I had done 20 images earlier last week and the alignment from a time lapse sequence with a small amount of camera shake turned out great. Not sure how many images you can do and why results are good one time and not the next.