Mark sent me a very prompt reply to the mail I copied in my previous post. Good to hear it's something he's already considering.
Very good to get this message while I'm at Debconf! I've been working to build consensus for this sort of idea in Debian for some time, because as you can imagine, maintaining the delta between Ubuntu and Debian is much easier in cases where the package has split out patches as you describe. I'll use your comments to bolster that argument even further.