Speaking of the party taking on Lord Soth, I've been idly coming up with ideas on how to continue the adventure should my group want to do so, and, obviously, Lord Soth makes for a perfect target. After completing the adventure, the characters should reach 12th level, so with a CR 19, I would think a well-equiped party at 15th level or so should find him a reasonable challenge. He wouldn't be permanently dead of course, as his curse won't allow that to happen, but it would likely put him out of action for some months at least. And luckily, with dragons (and the remnants of an army) around, there are plenty of reasonable targets to help with that leveling process.
As I've said before, I've been pondering converting the enchanted draconians from Dark Queen of Krynn to create some more higher-level challenges for this. And I'm thinking about creating a "greater dragonlance" for any campaign extension to reproduce something a bit stronger that would be closer to the original 1e item. Doing damage equal to the wielder's hit points is, as then, a bit over-powered, so I was thinking upping the damage from 3d6 to 10d6 force damage, and some other additional effect, such as negating the next successful recharge roll for the breath weapon (automatic, or have a DC?).