Here is an update on what I have been doing:
I tried to have a look at the optcode differences between the Vita and the PC version. But I noticed that the difference is much more complex then finding a new value for the same instructions. As an example the first line in the game:
PC: #0100001V#0001F#11PWell, Tio?
EVO: #0100001V#2B#11Z#19B#29Z#0001F#11Pどうだ……ティオ?
The codes: #0100001V / #0001F / #11 are coming back in the vita version, but there is also more information like #2B / #11Z /#19B /#29Z
Then I tried Dasutein his advise and tried looking in the ELF file for the optcodes . I used the following instructions:
https://forum.devchroma.nl/index.php?topic=88.0
I was able to decompile the ELF. But I do not have the skills to make any sense out of it.
So I gave up on the hole EDDecompiler methode
Then I tried the hard way. And that's manually changing the Japanese text with the English text. If I translate the first scene in the game. It works perfectly. But if I update the entire file all the offsets are screwed up because the text length is different. And until now I did not figure out how to correct this. Maybe EDDecompiler can give a hint.
So now I updated M3000.bin as EvilGoku did. but then with the geofront translations. And this works perfectly. So I think I'm going to continue that way. It is not the cleanest way. but it works. The only thing is that this is going to be a lot of work. And I would like to find some people who would like to help.
Now for the extra missions. I started with extracting the Japanese text from one of the extra missions (C0210_1). And I'm going to ask geofront if they would like to help and make a proper translation.
Edit: removed link