You fail to understand what I'm saying. It's already possible to retrieve save data for a GBA VC title on the 3DS. There's tools that exist to do this on the 3DS as it is. It's also already possible to inject whatever GBA games into GBA VC title CIAs on 3DS, just not on the 3DS itself yet because nobody has yet made an app to do it, just on Windows.
The process for this idea is as follows: App takes a GBA ROM, unpacks and injects it into a GBA VC title CIA (one on your SD card, so it wouldn't be fucking with the SysNand during this process), installs it then launches it just like if you had launched a GBA VC title. (Heck, if automatically launching it after isn't possible, just prompt them to click on the title on the home screen). You play just like you always would, when you're done playing, you close the game/restart the 3DS. After, you re-launch the app, it grabs the save data, and copies it to a file, named after the last ROM you loaded.
There's already something that exists that works in a very similar roundabout way, but for the NDS. (GBA Exploader runs in NDS mode from your Slot1 card (r4, DSTT, etc), and works by uploading a ROM to a special slot2 card, then launches in GBA mode, and when you're done playing, you reboot the NDS, and run GBA Exploader again, it grabs the SRAM from the slot2 card, and saves it back to a file on your Slot1 flashcart's SD named after the ROM you had picked before.)
