Being such a recent purchaser who was so wowed by one of the videos that I haven't even started playing the game yet before checking out the forums, I have to put in one reality check.
While over-complex bounds are of course nasty from a performance perspective, have people considered the option of having "lite" bounding boxes for "gentler" computers, and having full-on hardcore "I've got 10000 pixels!" bounding boxes for high-end rigs, and then releasing their mods with both options, or even a range of options in between? Have your cake and eat it too, so to speak: the people who insist that "perfection is the meaning of life" (where the journey is clearly the goal, because perfection can never be achieved) can have all of their endemic performance losses, the people who insist that "if it looks right, it's right" (like building contractors, right up until the thing collapses) can have their speedy optimised bounding boxes that allow holes to be blown in, well, holes.
I say this because once CPU power advances enough, perfect bounding boxes can be feasible in the long term. We're not facing a global gigahertz shortage within the next couple of decades, unlike certain other commodities. =)