Alternate Magic Rituals is described on page 9 of GURPS Magic as an alternate to the standard Magic Rituals rules.
Page 36 of GURPS Thaumatology broadens this to include a No Rituals option, and the initial system from M9 is renamed Flexible Rituals and further clarifies how it does not affect energy cost or casting time:
- "These modifiers don’t affect energy cost or casting time reductions."
T38 describes how it interacts with Easy Casting enhancement and Extravagant Rituals limitation for Magery.