Note: I realise this question is about an old version of Kickassets running on an old version of the CMS but someone might know a quick fix for this issue that might save me having to upgrade the entire CMS to version 3 just to solve this?

I have a client on SS2.4 with the KickAssets module installed, using a custom sort order for photos added to pages .i.e the _config.php file has

ManyManySortable::add_sortable_many_many_relations(array('Page' => 'Photos'));

The sort order works, but it reverts back to being ordered by name everytime a new file is added.
i.e. adding a new image to a page that already has multiple images set to a custom order will result in the whole list reverting to alphabetical.

When adding a new file, is there any way to leave the custom order set as it is, and just add the new file to the bottom (or top) of this?

It's been a while since I've had my head in this module, but I don't recognise this code at all:

ManyManySortable::add_sortable_many_many_relations(array('Page' => 'Photos'));

What does that come from?

Just looking back at these comments from 2012: http://www.leftandmain.com/silverstripe-modules/2011/08/25/kickassets/#comment-1012
It looks like I added that line to my config file in order to get MultipleFileAttachmentField to work. So this might be the issue - any idea? Is there another/better way to enable manual sort ordering?

I appreciate that you may not want to look through old/outdated code but if you have any ideas let me know, thanks

(ps. I can't get that link above to work)