I'm not sure what happened, but I seriously screwed up my spatial drives. I still haven't completely corrected it, but I wanted to post my experience here in case other people had the same issue.
I followed the procedure outlined in the first post to update spatial areas after a modpack update, but I apparently did something wrong. After the update, Miner's Delight was loaded by "default"...trying to reload it using the disk and then unload it, like Parcel showed in his "How to fix mismatched spatial drives" video, had no effect, it would stay Miner's Delight no matter what. Not a big deal, just annoying.
Go down the road a bit. I finished Idea Machine and went to load Ice Palace. The area that loaded was...odd, and I couldn't figure out why it was called Ice Palace, and I couldn't find the wool anywhere even though I tore the area apart at the seams. I started a new game and cheated my way through the book to the point I was at, loaded Ice Palace, and it was the right one. I then, on a hunch, cheated in Redstone Meltdown...and that was it. My Ice Palace was Redstone Meltdown in my LP game. Go back to my LP game, turn in the quest for Redstone Meltdown...and it's Redstone Meltdown too. WTF? Both Ice Palace and Redstone Meltdown were loading DIM33, even though Ice Palace is supposed to be DIM34...as a quick fix, I copied the DIM34 folder into DIM33, since I was done with Redstone Meltdown anyway, went into Ice Palace, found the wool, turned it in, and went to load Reds. And it was Ice Palace, loading DIM34...
Eventually, what I did was cheated in a bunch of blank 128 spatial storage drives, and followed Parcel's "load what's shown in there until it goes away" method, using a blank disk if something got stuck and wouldn't go away. I don't know what happened, and I don't know the proper method to fix it (or if there IS a proper method, since it appears that the dimension listing for the drives themselves is somehow screwed up, trying to recopy the folders does nothing to fix it), but it appears to work well enough to let me finish the modpack.
I've been debating taking everything out of my ME system, storing it in strongboxes, keeping the strongboxes on my person, and then copying my playerdata folder and the DIM-1 folder over to a clean save to see if that fixes it, but considering the sheer amount of crap I've accumulated that I'd have to either transfer over or lose (since I'm pretty sure storage drive information isn't stored in the playerdata folder), I'm saving that as a last resort.
On a related subject, could we get an updated dimension listing Parcel31u? There's several spatial areas that aren't included in the list, and it's impossible to spot-fix a corrupted save game without knowing exactly which dimension corresponds to which area without a LOT of experimentation and potentially spoiling upcoming challenges for yourself by seeing something you weren't supposed to see yet while screwing around with save file manipulation.