This is true for pretty much every wilderness except Orchard, though, for the same reasons - the XP/min compared to questing is just so horrible. It doesnt have to be equal (Slayers are way easier than R1 questing), but it has to at least be in the same ballpark
Increase spawn density in Barovia so that, like Orchard, you can actually clear Slayer goals in a reasonable time, without just doing runs down from Amber Temple over and over...
Maybe increase XP for Rare Encounters and Explorer objectives too, if not just increase the XP across the board