Justified Image Grid (Broken/Incompatible)

The plugin (v0.7.1) does not appear to work in tandem with “Justified Image Grid” (a gallery plugin that displays gallery thumbnails in a justified grid) and I cannot filter the relevant images, as they cannot be equipped with a class from the backend.

The error that occurs is that images are outputted as both the justified grid and full size linked separate images beneath the gallery – essentially as duplicates.

My images are nested within an anchor that has a class, but adding the class of the anchor element does not help. I tried attaching a class to all gallery images via jquery, but that did not work out (probably due to execution order).

So my question essentially is: Is there a way I can keep BJ Lazy Load from lazy loading gallery images and gallery thumbnails – but still lazy load all other images within the_content? (or alternatively: filter for anchor tags with a specific class within the content, that contain images)

https://wordpress.org/plugins/bj-lazy-load/