No!!!
Double Down on any number of cards means you can double down after receiving a hit card or two... or even three. Example: you are dealt a 2 and a 3. The dealer has a 5 showing. You take a hit, and get a 6, totalling 11. Now you can double down. Whereas with standard rules you could only hit again.
Typically games that offer "crazy rules" such as double down on any number of cards, will take away a rule that is good for the player. Often paying even or 6:5 on blackjacks.