Temporal Rift & Spirit Reservation

My Chronomancer apparently can't use Temporal Rift without 10+ unreserved spirit, which doesn't seem to be a requirement listed anywhere in game.

I've got only got 6 spirit left after reserving Blasphemy + Heightened Temp. Chains with Clarity supporting Rift. Rift won't activate like this (although I do get the Clarity effect), but if I disable Blasphemy or remove either of the Heightened Curse or Clarity supports to bring my unreserved spirit up Rift begins working again.

Bug ID: 3,165,660,552.

^up