The thermal design of the instrument must meet requirements in several areas. Optics are functional.
Detector is functional.
The cooldown of refractive optics cannot be so rapid that they are over-stressed. A pre-cooling system is not currently under consideration. Concerns with such a system include weight and cost. Venting and handling facilities must be provided both at NOAO and at Gemini if this capability is a permanent part of the instrument. Note also that the operating temperature of the instrument is significantly cooler than the temperature of liquid nitrogen, so that the design must include provisions to avoid turning the pre-cool system into a heat source during operations, among other considerations.