You might already be aware of this, but Chrome has a...ahem...wonderful little bug in it that causes it to time out on some image-heavy sites, thus only partially downloading the images.
My issue is that my site has large enough image galleries (and images) that it's triggering this timeout (and I get an endless loading overlay). I noticed when looking at the rendered code that the page renders all of the images, even if they're not all visible.
What I was thinking was a way to sort of "optimize" the loading time for the galleries by, perhaps, only rendering the visible ones. However, I don't know if that's even possible, and since you seem to be more familiar with image galleries in general, I was wondering if you'd have some insight into that. I'm thinking it'd be on the PHP end, where it only retrieves the X set of images, though I'm not seeing anything obvious in your code for getting the images and putting them in the generated list. Also, if I understand how SilverStripe handles images and thumbnails (the _resampled folder), the thumbnails are already generated, as I loaded up the galleries in a different browser, first. So, unless SS rebuilds the thumbnails every time, the hangup shouldn't be in that generation sequence.
I understand that this solution would result in longer load times between gallery pages, but it would lower the initial load time and (theoretically) allow visitors using Chrome to load the galleries at all.
So, would that be possible (at least with Image_Gallery/SS)? If so, which function is controlling that? If not, do you suppose there's another way I could work around Chrome's bug?