I believe the problem with TWL was not because they were using the DS Profile exploit, but rather because TWL had to reset the whole console, and if it resets the whole console, it disabled emuNAND.
The problem with that is that, in emuNAND, you have the custom program to launch the DS game, and also the DS game as well.
As soon as you reset the console, and Gateway mode is dis-engaged and no longer tells the NAND to redirect to the SD card, you can no longer boot into anything that was on the SD card, because you just disabled access to the SD card via emuNAND, which you used to boot the DS game.
You can already try this, open up emuNAND and load a DS cartridge. It won't work.