I think an "exercise or surrender" sort of clause would do wonders. Of course, the patent system is brutally complicated and rife with unintended consequences, so tinkering with it is pretty fraught. The world isn't a theorem to be proved, there's no right answer. We all have to learn to deal with ambiguity better.
A windfall profits tax on transferred IP would be interesting, so IV and the like couldn't suck all the value out of the tech industry.