To say that I have enjoyed playing BG2 more with Imoen4Ever would be putting it mildly. I have been playing BG2 the way I played BG2 - with a focus on exploration and adventure. (I also added tweaks to enable any non-plot related lands, such as the North Forest). I've also roamed all of the places Lava has added. It's been a wonderful romp through BG2 unlike any other.
However, I now see the pacing problems by doing things this way more clearly. My party just wrapped up Watcher's Keep in Chapter 3. They opted not to fight the imprisoned one, but that whole area is done. They did leave Saladrex, because while he is a jerk, he wasn't actively hostile.
Which means that the party was very high level when they left for Brynnlaw. Isra and Sirene were both level 19 paladins, Jaheira was 14/14, Imoen was a level 19 mage, Aerie was 14/14, and Eilrie was just shy of level 20 right before getting on the boat. Which meant everyone except Aerie had HLAs. While on the island, everyone leveled, and got even more HLAs.
Now, in the Suhagin city, Isra and Sirene are both level 20, have greater whirlwind and summon deva, and are loaded out with +4 and +5 weapons. Jaheira is now 14/15, and can summon earth elementals, Imoen is level 20 and has both alacrity and summon planetar, Eilrie, the sorcereress, is just nuts - especially with the robe of vecna and some other items that improve her casting speed. She can time stop on a dime and drop all manner of nasties on a crowd.
All of this has made chapter 4 and (so far) chapter 5 feel a LOT different. It also apparently short circuited a few things. Eilrie never transformed into the slayer in the basement, and I'm still not sure why. When they confronted Irenicus, Isra, Sirene, and Jaheira (now all three equipped with boots of speed) had him down to near death before he got his casting finger up. Eilrie hammered him so hard that he gave up before he had a chance to cast a single spell. (I was still saddened to see that there is no way to save the other prisoners...) It's like playing on easy mode, but I haven't "cheated" at all.
Other than using the console to fix things like NPCs not showing up, I haven't used the console to boost stats, give powerful items, etc. The party just did everything they could before getting on the boat. They were at day 328 when they left, and were actually just sleeping a lot to get through one of the stronghold quests.
The silver lining is that the party can now RP the way they would like. That "fest hall" in Brynnlaw? Yeah, Isra and Sirene weren't amused, so the party nuked that place six ways to Sunday. Tearing slavers new backsides has become their hobby.
I may up the difficulty to tactical from core rules to see if that returns the challenge.