Haha, yeah, I like everything as perfect as possibleQuite a perfectionist aren't we? Well I can't blame you, I'm the same... My guess is you might be able to mess with the "main.dol" file, like I did so the names of the characters wouldn't appear in Japanese (something I discovered AFTER releasing the first edition of the patch, since Earth Seeker worked totally differently ), but it's just a guess.
Or it could be related with console detection, since to my knowledge the text appears in gibberish on every non-japanese console (and doesn't on Dolphin).
To be honest I'm not sure of what I would be doing there, so if someone has a suggestion and does some tests on a modified ISO I'm opened to it : but in the end, I think it's more related to game identification than to modifying text per say.
I supose it checks the game disc region and show that screen according to the game. No idea of how to change that...
About the translation, I found something weird. I put the game yesterday and it seems that if you have an additional controller conected (classic controler, nunchuk, etc...) the game shows a black screen with a message, but it only shows random characters (I though the game was broken because I didn't notice I had the Nunchuk connected and the other buttons doesn't work in that screen). I supose that screen should say something like "Please, disconnect aditional controllers." or something like that, no idea...
That screen appear any time if you connect something to the WiiMote