Show longer captions in lightbox

I would love more options for customizing photo gallery captions in lightbox, like having the caption appear over the image on hover as opposed to underneath the image. This is already what happens in the Advanced Gallery block anyway, until you click for a lightbox and then hover isn’t an option anymore.

Or alternatively, if the caption has to stay underneath the photo in lightbox, I’d love for it to be scrollable. Currently when you have a really long caption, it scrolls on hover, but not on lightbox. So I have to just turn captions all the way off in lightbox, because if I keep them, the caption takes up the whole page and the photo gets shoved out of view.

Or what if lightbox could create a pane with the image on the left and caption on the right? Attached is a screenshot of what a lightbox looks like on Pinterest, a panel with the image on the left and the description on the right as opposed to underneath. This would create a lot more space for the caption, you'd have the entire right side.