The block times doesn't matter for merge mining.
A coin with a 10 minute block time can merge mine with a coin with a 1 minute block time.
so zet can merge and doesn't need change? This would be great news for both coins, wouldn't it?
Yes, the parameters doesn't need to change, but one of the coins must implement AuxPow.
If a coin has AuxPow it can merge mine with other coins that doesn't have AuxPow.