It's very common in japan for contracts with voice actors and/or recording studios to only allow their work to be used for domestic release only, in that case, Namco wouldn't be able to make the game dual audio without create a whole different Japanese audio.
Contracts that allow non-domestic release would most likely be more expensive and most Tales of games don't even get localized, so It wouldn't be worth it. Not only that, There is no guarantee that dual audio would boost the sales. In the end, It all comes down to cutting costs, dual audio doesn't benefit Namco at all.
Thank you mamu, really I can't wait to be able to play this game in my favourite spoken language in japanese games. This was really a great experience with Graces and I was able to enjoy it thanks to you. I did my work too, and collected all the data we could use. And to celebrate the coming undub version I wanted to share with everyone some good news and presents.
In fact, To ensure that we have the best undub version with lip synch using the JPN version would be the best. And like last time, there is a double advantage to use the BLJS version. The japanese voices of course and the possibility to add any language sub text we want using the Euro version or English using the US version.
And the others, not the less, the possibility to use the already fixed EBOOT for 3.55 CFW user that don't want to update to the latest and FINALLY DLC even if those DLC contains SKIT dubbed in japanese and with subtext in JPN, those could works without any problem using the JPN version. That way people will be able to use all the content, new costume sets based on other anime or games, items and Bonus. And that's the great news since... HUM, I got all those DLC.
All the DLC available until today, which mean everything could be added since the start. And to celebrate I wanted to share a little more than those DLC for Tales of Xillia, exciting isn't it?
You have to extract the game (obviously you need to have the game files in your pc) using mamu's toxpack.exe, then I guess you use mamu's sdb editor to edit the English text in, in the respective extracted files. Here are the tools I collected: