Carry-forward is certainly what we have been doing this year and will do for next season.
However, there is a little fly in the ointment. In the re-alignment phase of NHC calculations the base numbers for the boats which took part in the race are used.
As I'm sure most people do (although I am indebted to Jon for this tip) when I get to the end of a series I display the ratings, using the 'extra' column, then create a new series with that extra column as R1, so that the NHC values are in there, ready to be used instead of the values in the column headed Rating, which hold the base numbers.
If you use the last race+1 'ratings' to populate the Ratings column then things will not follow the RYA protocol.
Which brings us back to the importance of getting the base numbers right, since they are always going to be with us.
Malcolm Clark (Flushing Sailing Club)