dang, but what if it send a DSiWare format homebrew?
still no. Permissions are given and handled at the start of a application being started and is given by a case by case bases. In other words, when the 3ds loads ds download play. The app itself tells the 3ds it doesn't need nand access or sd access. It locks those permissions and then loads. So even if you sent a dsiware format homebrew, it would mean nothing. Since ds download play has already said to the system that nand and sd card access are unneeded. (feel free anyone to correct me if I misunderstood this)
Now yes, ds download play does load from nand. However during the process of permissions. It just copies ds download play to memory/ram. And then continues loading as normal. So you still wouldn't have nand access even if it does load from the nand.
And it runs in ntr mode. Which is a issue. Since dsiware formated homebrew need well... twl mode.