>Done right this could set them up for life and make them millionaires with virtually no effort by the age of 30
This seems hyperbolic. Given that money doubles in roughly 10 years at a 10% rate of return, if kiddos are 10 years old they get two doublings by 30. To be a millionaire by 30 requires a present value investment of $250k per child.
You should take inflation into consideration, so the million in 20 years won't be the same as now.
It’s been my experience that when people are talking about some future sum of money without specifying real or nominal they are referring to a real sum, based on their current day concept of monetary value.