Not sure if bug or suggestion:
The fight with the phase spiders seems to have very poor xp rewards when compared to other encounters. Each phase spider is 5xp, and the matriarch (acidball spitting, 138 hp, phasing, summoning ) is only worth 20xp. As a comparison, the red caps are worth 50xp each...

Bug:
During level up as wizard (3rd to 4th): I already have acid arrow and detect thoughts in my spell book from copying a scroll. However, the default level up selected both acid arrow and detect thoughts for my level up spells, and even customize doesn't seem to indicate that I already know these spells and should select others. It also set my memorized spell list back to some default or previous set of spells, forcing me to re-select my prepared spell list after leaving the level up screen (especially since it doesn't show spells from scrolls in the level up screen prepare list). Bottom line: learning a spell from a scroll isn't being taken into account for wizard level up.