Enfold 2.9 lightbox: exclude featured image (or png format)

Hi,

I really like the new lightbox in 2.9! But I’d like to exclude the featured image of a post in the lightbox.
Suppose I have a blog item with 3 images and a featured image. When I click on the last image the lightbos says
3/4 and when I click the next image button it will show the featured image and not the first image from my blog item.

At the moment my featured images are png’s and the lightbox I’m using right now excludes png’s.
Is there a way to let the new lightbox exclude the featured image or png’s?

Best regards,
Arjan