* Torque Management: Nitrous oxide dramatically increases torque. In reverse, this massive increase in torque could easily overwhelm the drivetrain, causing significant damage to the transmission, axles, or other components. The drivetrain isn't designed to handle that much power in that direction.
* Engine Load: The engine is not optimized for reverse operation under high load. The added strain of the nitrous could lead to engine damage.
* Safety Concerns: The increased power and potential for loss of control are exponentially amplified in reverse. It's incredibly dangerous.
In short, while technically possible to activate the nitrous system, it's impractical and extremely risky, making it something that should never be attempted.
