Well, not much luck here, I guess.
Thankfully, I hit upon a solution on my own. I was planning to help matters a bit by installing a script that only loaded thread images when they were scrolled into view, at least, which is a nice start. If someone wants to keep things really simple and go that route, echo.js is a good solution, and very lightweight.
I'd still be interested in any other methods people have found to achieve this sort of thing.