I hope this can shed some light on the issue:
I know what is wrong with the triple boot for the iTouch, but I have no means to fix it. I can, however make changes to the firmware that will cause different effects on the M3 Real and Sakura firmwares. The problem is caused by the file G6DSload.eng (and possibly a couple of other files) that exist in both the Sakura and M3 Real firmwares in the same directory. Theses files can be swapped to get some different effects. Itouch firmware will work regardless, however if there is an update I can't update it because I don't have the tools to do so.
I can compile any of the following for the iTouch with the files I have:
1. Sakura Only
2. Sakura and iTouch in English.
3. Working Sakura, M3 Real working in Japanese, ITouch in English
4. Crippled Sakura, Fully working M3 Real and iTouch in English (which is in circulation)
EDIT: 5. Today I accidentally discovered a combo where M3 Real Boots, btu can't load backups or homebrew. However, M3 Sakura is flawless, as far as I can tell. I touch is also unaffected.
I CAN NOT compile a release where both M3 Real and Sakura firmwares are fully working in English.
@tguellich: The reason that this is happening is because M3 Real firmware newer than 3.7 will not load on the iTouch. I assume that the M3/G6 team added some code to prevent this, which is perfectly reasonable on their part. This is the M3 firmware's problem. I will look at the new loaders files, however and see if I can't fix the problem we're having with Sakura.
If anyone knows how to fix the problem, please contact me.
Edit: After making a decision about the quality of the M3 Real firmware, I am making a final compilation. A Sakura-iTouch double boot. Sakura can load backups, load some important homebrew, like GBA EXPloader, and iTouch can handle homebrew games, so M3 Real firmware is unnecessary. I'll still answer any PMs about my other releases, if anyone with an iTouch wants a hand.