When processing a large number of input files there is a problem with the sortorder applied by PA when creating the groups. PA obviously sorts the files by filename, but simply alphanumeric.
filenames are 2012-01-01-1 to 2012-01-01-1500.
In this set of 1500 input imgs and grouping them into groups of 30 images and if there are no leading zeros in the image sequence numbers applied by the camera (like 2012-01-01-0001) then PA sorts them 1,10,100,11,...,1500,2,20,21,210,22,....
This is correct from a pure alphanumeric sortorder approach applied to the filenames but it is not the sequence the images have been taken.
But I would prefer to have the sortorder numerical based on the sequence number as follows: 1,..,9,10,..19, and so on.
This would allow to process images from a camera which does not apply leading zeros.
Adobe Lightroom and Windows Explorer have this sortorder by default, so it took some time for me to detect why the group assignment in PA was "wrong" sometimes.
As a workaround I always have to remember to add leading zeros to the filesequence numbers on import time to avoid later problems when grouping them in PA.
I know that such an adjusted "intelligent" sortorder is not an easy task but I would welcome it very much.