Does MIgraine and Arcane conundrum stack?

Just curious if anyone knows if Migraine and arcane conundrum stack (resulting in a 4x casting time). If so how did u find out?

Yes, and x4 is the max you can stack anti-cast time debuffs. I just tested tonight with some friends. I tried to combo Archane Conundrum and Migraine... of course it worked fine and the 2 second spell came out in 8 seconds. I then tried to combine those two with Concussion (x3 casting time on spell interrupt). Unfortunately, it didn't cause a x12 effect. I tried Concussion then Migraine... instead of x6 effect (making it a 12 second cast on a 2 second spell), it still came out in 8 seconds. So the cap in any combination is always 4x.

I wanted to see if those three skills stacked and whether adding Nature's Renewal would cause all casts to be 24x. o_O No dice. Reversal of Fortune was saved from becoming a three second cast, lol. Plus, I would have made a video of Restore Life's 192 second cast just for kicks.

Actually, Restore Life wouldn't be a 192 second cast because Migraine and Arcane Conundrum don't last 192 seconds. Correct me if I'm wrong, but the casting time of a spell isn't locked in when it first starts to be cast... It is constantly updated if conditions that affect the casting time wear off part way thru the casting.