Preload by “Class”

Hello friend, hope you are well. Have marked as: This topic is not a support question. Because it is more of a feature/settings request.

I write in hopes the developer can find the time to implement letting the user chose images to preload not only by url but also by class name. I have hundreds of posts and want to preload my featured images that are above the fold, adding the url for each post in the post editor would take far too much time and effort. I was hoping we could add such request to the plugin as for example: Preload on Post: attachment-my-themes-featured-wp-post-image

Thanks for listening, respectfully.