Removed down travel bumpstops, and replaced the up travel bumpstops with low-profile units. Significantly improved travel in both directions. I will be adding some sort of poly bumpstop to the down travel stop after I modify the bumpstop rest on the frame (going to cut it down a little to relocate the stop after I measure a bit and figure out how low the geometry/shock/CV joint will let me go). I reckon there's another inch or two of downtravel to be had without too much fuss.
Here's the same section of trail before this round of tinkering (not positioned exactly the same, but pretty close...also on 31's):
After, on 33's:
...the front hub is now completely above the rocker panel line, as compared to the first photo. Also note how much more level the truck is, as there's more room for the suspension to conform to the terrain before hitting the stop and forcing the truck to list over to the side.