There's no Lua in Fire Emblem. Everything is baked into one executable, so hacks are done at runtime with native code.

Oddly enough there's a bunch of mentions of FA5J which is the Wii Virtual Console game ID of Fire Emblem.

Mind you Lua is only a means to perform hacks, they could have used Python, or some kind of bytecode, or native code. It's just about how to program the hacks.

Funny, the codename seems to be "Steel-S"?

...did NERD actually work on this? Because I'm genuinely having doubts as I see mentions of VESSEL, which is the Wii U emulator name..?

Wait, did they really take the Wii VC release as a base and then change the codebase? Is that why the game is dimmed?

...Hypothesis: "Steel-S"... usually -S is added when it's a Switch port. Is this localization much older than we think?

I'm suspecting that this was done back on Wii U because Vessel is the name of the NES emulator on Wii U, then ported to Switch?

If they wanna develop this in a way where they could put everything under the same app with a single emulator like the rumor said, this has to be redeveloped from the ground up.

Now this is seriously making me think, like, how many localizations have they done in the same manner back then..? Mother 3?

I must mention this but yes, Vessel is both NES and N64.

It seems this is the work of Intelligent Systems and Nintendo according to the manual.

Since I have to talk about the 4chan post again:

The original post said that Nintendo was picky on what could have been considered authentic, judging by how the project may have been done on Wii U, this is completely false.

I want to link this tweet showcasing the differences in color between Vessel (Wii U VC) and Kachikachi (NES Mini / Switch Online): https://twitter.com/Zetsuboushitta/status/1334844991412301829

I want to add this: I do not think this is lazy. They did a lot of work here, just that it is based on the previous NES emulator instead.

Also, EarthBound Beginnings is literally the final English ROM that was made in 1990. Aka the english prototype that was dumped a long time ago, which we now know is final.

If it's not obvious: No, you can't take the ROM and expect it to be in english. The english text is hacked in real time.