I use Responsive Lightbox – PhotoSwipe 1.1.1 on my Foogallery premium. (FooGallery version: 1.4.31, WordPress version: 4.9.8, PHP version: 5.6.38)
If the PhotoSwipe plugin is active and PhotoSwipe is selected as a lightbox, all of the Gallery’s original images are loaded in the background.
Example
With “PhotoSwipe 1.1.1” Total Page Size 17.4 MB 142 Requests: https://tat9.seoprofi24.com/at/tattoo-fotos/farbe/
Only with standard “Image Lightbox”: Total Page Size 2,11 MB 40 Requests:
Could you please give me additional help?