(Somewhat) Consistent Instance Crashing - Seemingly related to Delirium

Title.

I've been getting some instance crashes lately. The game suddenly freezes and my ping begins to spike. When I pause the game, the ping goes back down after a while. Then after I unpause, maybe a tenth of a second goes forward. This repeats for a while. Sometimes the game eventually gets out of the cycle and continues, other times it crashes the instance.

I haven't been experiencing any instance crashes since the last patch (0.2.0h), but today I started running some Delirium (of the mirror variety), with the "They're coming for you" Delirium node allocated (and no others).
Every single time this problem popped up, instance crash or not, it's been pretty late into the map while Delirium is still up, and I was up against a densely populated screen of monsters.

I tried forcibly ending the Delirium encounter during the crash peekaboo, but it didn't seem to help.

Maybe it's some sort of skill interaction with the game freaking out when Dark Effigy or Contagion have too many viable targets at once? Iunno. Maybe that's relevant, maybe not.