On the subject of hate bears:

While I agree that the white splash isn't worth it for Thalia or Canonist because Sphere effects without color requirements are better, I have been testing a Bayou main for four Dark Confidants in the side. If you run them with Chalice of the Void, you can board them in against both removal heavy decks with Swords and Lightning Bolt and against combo decks. The extra card seems way worth it in these matches. Board could look something like this:

4 Krosan Grip (maybe 3/1 split with Abrupt Decay, since you're splashing black, but you don't wanna overload on black cards for fear of missing mana requirements)
4 Chalice of the Void
4 Dark Confidant
2 Trinisphere (in this Omnitell meta, though I'd switch them to Spheres in a Storm meta)
1 Dark Depths

Whenever your board in Chalice, the only viable option is to board out all one-mana spells besides Exploration, but that's okay if you have Dark Confidant because it can replace Gamble as your consistency card. I wouldn't board this way against Delver decks, and probably not Midrange since Chalice won't have as much of an effect against decks with loads of answers, but I definitely would board into Confidants and Chalices against combo and Miracles.