I’m pretty sure that the base game is the issue here, not the mod. Still, maybe someone has a suggestion as to how it can be improved.
One more thing: I feel the xp progression in Act 6 is sub-par. I normally enter Hell Act 6 somewhere in the mid-80s. On average I only gain 2 levels in the whole act, which pales in comparison to Act 5, in which you got the Foothills and the Summit encounter (a full level-up on Hell).
This isn’t helped by the fact that levels 10-12 are very tedious to navigate and have these annoying rock monsters plastered all over, which stop you dead in your tracks when you touch them. So I generally semi-clear 1-9, then run through most of 10-12, then start clearing again from level 13 onwards. Still, even with quest rewards I only manage to get said two levels.
I compared the XP for same mob types in the two acts and it seems they only increase marginally for my level 87 char. A level 92 succubus in the Frozen River gives 1049xp, a level 102 succubus in level 14 gives 1192xp. That 13,5% seems too low for a 10 level difference, since the level 102 succubus has almost twice the hp. So you’d be stupid to farm the higher level zone, since you can clear the lower one almost twice as fast. Levels 14-16 also have a substantial amount of caster mobs, those stand more spread out and tend to not clump together too well, which makes clearing even slower in comparison.
In my opinion, such a thing should never be the case. Players should always be encouraged to tackle higher zones. If you punish them by giving them less xp/hour in return, you condition them to always go for the path of least resistance. So mob xp in Act 6 needs be increased to make it a viable place for farming, cause right now it’s not.
EDIT: Just finished the campaign and I think I found an issue with item persistance. Diablo dropped the set item “Spike Thorn”. When I picked it up, the map indicator was still visible. When I dropped it again, another star was added, which also remained there. I gave Diablo’s place a makeover with this, now it’s a fabulous crib. I tried it with another green item in my inventory, but only the shield showed that behaviour. I could replicate this in any zone and even after relog, so it seems that it’s not tied to the current session.