When frosted ice ages it's data value goes up by 1 per age (tested with the testforblock command)
But whenever you try to setblock frosted ice with that age, it's age will be 0 under any circumstances.

/setblock 6 47 -46 minecraft:frosted_ice 2

should have set frosted ice with age 2, but it sets frosted ice with age 0.

This is really inconsistent when you consider that cloning frosted ice with different ages works.