So there's just no practical way to increase the data rate much?
Guess we'll just have to move Pluto closer for the next mission.
(space is just so damn big and empty that, per Hofstadter's Law, it boggles me to contemplate even when I think I've pre-boggled myself. Unless wormholes and ansibles come to save us I fear humanity will live and die out here in the solar system, just possibly managing to exchange very slow postcards with alien penpals)