I don't know of any way to spawn quest items.
You could try emailing email@example.com.
I don't want to do that. I got the games for free, but I'm not able to write a review (personal reasons). It would be a bit unfair to expect Larian to invest time ( = money) if they don't get anything in return.
But given that I'm running into A bugs every couple of hours it's maybe even good that I'm not writing the review.
I found Alrik by accident. He was teleported to another point, the left tower in the castle ruins where the dragon cult is at home. When I wanted to open the crate on top of the tower, Alrik was suddenly at the lowest level.
Xantosch (sp?) and his pet also disappeared, never to be seen again. Which means I cannot complete the Ulthring set.
The first necro quest in the undead cave in the south of the fjords also failed because the relevant monster wasn't there.
The thing all mentioned cases have in common is:
A critical NPC should be spawned, but it doesn't happen.
Alrik spawned at a different place. This could hint at a world-coordinates problem. Maybe it's as simple as that: The NPCs spawn, but the table with the locations got mixed up.
After browsing the German tech forum I think I can safely say it's relatively common problem for people playing with the add-on.