Man, apparently the time remapping thing had nothing to do with it. Probably just a lucky coincidence at some point. It's taking forever to render again.
I guess dynamic link just wasn't made to be used with heavy comps... which is unfortunate, because that's usually when you need it the most. At least in my case.
Edit: Apparently Adobe Media Enconder does make use of full AE rendering capabilities. I just hadn't used AME in a long time because there was no point for my kind of work (I just exported directly from PPro), but now it makes a whole lot of sense. All's good after all.