Does a split after a double down gives you a better advantange?

I was wonder if a split after a double down gives more advantage to the player? Baileys has a new Single 21 that has the following rules below that gives me a .35 advantage. I think I get a higher advantage when I can split after a double down.

1. Allows you to split and double anytime even on the 5th card.
2. 6 cards without bust is automatic win
3. BJ pays 1:1
4. Late surrender anytime
5. Surrender on ace
6. You can split after a double down. If I have a 2,5,4 in that order and I double down and get another 4, I can split the 4s and get another double down card on the original double down.
7. You double down after a split.
8. Split aces one time.
9. One deck with one burn card.