My idea would mean more interest by far more players in future lotteries, the more winners there is (even if by low values compared to #1 prize), the more people will be wanting to participate, more money to your pocket.
Everybody wins.
Something like 75% to #1, 20% to #2, 5% to #3 (of the prize cake, not including your share).
Also adding a prize marker or date to complete, and start a new one, is a must have for obvious reasons.
Cheers