Gaseous CO2 won't hurt anything going down an intake except your power.
You really don't want cold fuel. You want cold air, and fuel vapor. Fuel vaporizes better when hot, hence the exhaust crossover on old street intakes. The only reason the cool can did anything (which I've never seen on a dyno) was because it cooled the fuel, and the fuel absorbed heat from the air to vaporize (which is kind of the same benefit as a fresh air intake).
If it's too cold, it simply won't have time to vaporize from carburation to intake. You're wanting to try to take it close to sublimation.
If you're that worried about it, run alcohol.
