3G's isn't much, we have roller Costers that do much higher than that.
Tower of Terror 6.3G South Africa (Johannesburg)
Shock Wave 5.9G USA (Texas)
Detonator 5.5G UK (Surry)
Revolution 4.9G USA (California) 1976
Don't get me wrong, I would love to see it added. Mostly because it would add the Coriolis effect, and development has already said probably not.