Chris, You already have the options built in that will aid you in sorting any way you wish.
Click on VIEW and select Thumb Sort. As you can see from the screen snap 015. and see if Presort by orientation will work.
If not exactly what you want, then see RATINGS in screen snap 016. Just apply a rating to the image which gives you the ability to sort by ratings and you set the rating as you finish your editing, or anytime with a right click on the thumbs. So you can change your.
 mind easily




.

Just wondering, how many different aspect ratios do you normally deal with up there on Neptune?  I ask because I was thinking that another way to address this would be by filename - or maybe a filename prefix associated with each aspect ratio - then sort by file name.

One rule I always use is to not add niche features for one person, else the software gets very messy.  I'm pretty sure you are the only person who would ever use that feature.

There is a way to do this, however.  Let's say you want to work with the 5x5 (1:1) aspect ratio images.  Select Intellicenter placement with the sort button ON.  Add all images at a size of 5x5 with crop off.  The sorting will put all the 5x5 prints first in the live view so find the page with the first print that is smaller than 5x5 and delete all prints from that point to the end, leaving you with all 5x5 prints which is what you wanted.  From there, you can go through the live view and select which ones you want to print, or rate them, etc.  In this case, adding all images at 5x5 with crop off will result in the live view:

(1) Having a group of 5x5 prints - these are the ones you want, followed by...
(2) A group of 3.33x6 prints - these were the 4x6 images
(3) A group of 4x5 prints - the 4x5 images fit in the 5x5 size without cropping but are still smaller

This works no matter what aspect ratio you pick.  If you want the 4x6's for example, use 4x6 size with crop off.  The only ones (the biggest ones) that will be 4x6 are the 4x6 (2:3) ratio images; the rest will be smaller and will sort at the end of the live view (queue).

Regards,
Mike