What I am tending to do is allow AS to keep their "real" age if it is more than +/-1 year, and entering the age given on the census in the 'text' transcription. I certainly do this for 1841.
If a person is, say 32 in 1851 then 41 or 43 in 1861, I do put this in the data entry part.
If I don't know an age with reasonable certainty, I enter the ages as given.
What's best practice? Is there anything I should be aware of (I haven't found too many problems this way, just the occasional