I don't need to tell you you're wrong here. Everyone else has. So I won't.
To answer your question:
I can tell you is that GBA VC games involve rebooting the system, which, because reboots push the console through the bootloader and firm load again, takes you out of EmuNAND. This makes MenuHax and EmuNAND in general a large hassle to deal with for GBA firmware mode, requiring the games to be installed twice to the SD card, once in EmuNAND and SysNAND, and in addition, Gateway doesn't normally work with GBA games to begin with, so it may work if you manually install a patched AGBFIRM in SysNAND, but I honestly can't say for sure, probably not.
You emulation options are: RetroArch GPSP core, or mGBA.
Neither are particularly good options, to be frank. GPSP is debatably playable on n3DS, but since you have an o3DS, I can't recommend it.
mGBA might be something worth a look once it gets optimized better for this platform, ARM Dynrec is planned for one of the next couple milestone versions of it, so maybe check back in several months and see where it's at.
To be completely honest, I wouldn't count on playable GBA emulation on o3DS ever happening, frankly.
Basically, the most viable option you have is something you are unwilling to more toward, I suggest you consider not being stubborn and maybe listen to the mostly reasonable, knowledgeable people of this community because despite some of them being rude, they know what they're talking about.
What I also can tell you, is that if you continue to ignore reason and just carry on parading your Gateway on your forehead like it's some sort of pissing contest, you're not going to have much luck with this community getting support, and you'll likely be ridiculed a lot more than you already are.
In the mean time, I'll carry on playing Yoshi's Island and dozens of other GBA games on my console.
Have fun waiting that Gateway GBA support Soon™.