Partner/Logo Element Bug – Can't Reuse Images

I discovered this bug while attempting to make a bios section for a cast of actors. What I want is a series of thumbnails which shows their name when the user hovers over the thumbnails and shows a lightbox when the user clicks the image. (Ideally I’d also like the lightbox to contain each actor’s bio, but that’s for another question, unless you can point me in the right direction).

The problem is, there are a number of actors for whom I don’t have a headshot, so I want to use a default placeholder image for those people. If I use the same image repeatedly, or I omit the image for a given slide within the partner/logo element, every time except the first time the image is used the image will be skipped, but the captions will remain, so the captions get out of line with the images. Obviously, a workaround would be uploading as many copies of the placeholder image as necessary, but that’s terrible for bandwidth since the user would need to download several copies of the same image.

It appears this is due to how the class avia_partner_logo is designed in logoslider.php. Around line 361 there is code to re-sort the slides in the partner/logo element so that each slide’s ID matches the “post” ID, where the “post” is the image (I think). If you try to use the same image for multiple slides within the partner/logo element, it won’t store multiple copies of the slide since the array is indexed by the image ID (I think).

Are there any workarounds? I’d like to refer to the same placeholder image and not have dozens of copies in my media library. Also, if anyone can recommend a way to add text to the lightbox (preferably HTML, but OK if not), that would be very welcome too.