I know what the Wii U code looks like, that's why I spent 60 hours looking into it, because like you I thought it would be simple enough. I know from experience it's not that simple. I, like you missed a huge red flag which was if it was that simple, it would exist by now.
Some things are just not that simple. A good example is this Infinite Hearts cheat Im working on for Hyrule Warriors. It's simple on the Wii U, and simple enough on the 3DS, but the Switch for some reason is much more complex for reasons Im still trying to figure out. Unlike the 3DS version of the game the address for HP is dynamic, and changes everytime you change characters. (and oddly enough the value for health is slightly different as well.) So the codes I made for both the Wii U version and the 3DS version just simply break when I port them over to the Switch version.
Im not saying that BotW is doing the same thing, but I am saying that although most ports are the same there are exceptions to the rule and you can't just blindly say, "but it was simple enough on the Wii U"