The Archivist ability's description is that it gives +1 lore per goody hut, and +5 lore per completed quest. The Master Archivist ability's description is that it gives twice that, and an equal amount of sovereign skill.
Instead, playing version 1.5 with the Tinker sovereign and the Master Archivist ability, gaining lore with that ability gives a lot more than that. That's not the bad part. The bad part is that it also increases the lore gained each subsequent time that ability triggers on the same turn. Popping a goody hut or clearing a lair adds 2 to this build-up, completing a quest adds 10, so that if opening a chest grants 7 lore, the next one grants 9, the one after that 11... this build-up can easily grant dozens of points of lore per chest.
Getting a few extra points of lore would just be fun. This bug is really a bother. I have to pick spells I don't want to use and keep the amount of chests I open per turn very low just to avoid blowing the game wide open. But that in turn is getting in the way of beating the game, since as the Tinker my skillset is geared around going on a chest-grabbing, lair-clearing, quest-completing rampage across the game map, not shying away from those things. In fact one of my other abilities litters the ground with chests that I haven't been able to gather because of this bug.
Or I could avoid the bug by not picking these abilities, but that would be playing with one hand tied behind my back. And increasing the difficulty level got me slaughtered.
I see I missed the 1.4 -> 1.5 patch, but here's hoping this won't take half a year to fix - the Tinker's my favorite class.
I've opened a support ticket over the issue, and here's a save.