I'm working on a little animation here and it seems what's going to utterly murder the render time will be the need to crank the minimum sampling up to 0 in order for some high-contrast text in textures to be legible. I suppose if I was a pro I'd do the text separately and composite it.... Any other ideas?
perhaps you could slightly blur the "text" regions of the image?
If you want to blur the text, then the Advanced texture lets you do that (just vary the EWA setting), or you could use the Resample texture, I think. But it sounds like what you really want is to do the opposite - you want to have adaptive sampling such that that texture with the text comes out really crisp, while the rest of your image is rendered with lower settings for speed.
It seems like the Resample texture could actually be used to do this - you can set a Min. sampling for that texture... but then I guess this sampling occurs before Brazil's sampling for the rendering itself, so maybe not.
I think rendering a separate pass is the wise way to do this: i.e. render the scene in two passes, one where that texture is absent (so you get the overall scene), and one where only the object with the texture is present (you could put a matte material on the other objects, or whatever you need to do to be able to create the mask you need for the compositing). I think that's what you're implying when you say 'do the text separately'...
I just brute-forced it in the end, if I was doing it today I'd probably try to wrap my head around video editing and do it in passes. The ability to specify AA sampling for an object/material/something is I believe an existing request, it does seem to be an issue with using texture maps in general...but then where you have the option to use procedurals instead(not this case, this is a bit of a tangent)they can look uglier at comparable settings because there's no equivalent of the "filtering" options.