L10N Compatibility Question [Adding Japanese / NA]

Hello staff,



Currently, there is Russian, Chinese and English language support available for this game. I would like to now also add and test NA and Japanese support.
Before I begin randomly downloading NA and Japanese clients and bruteforcing my way through this process, I want to ask you guys whether the current \L10N\XXX folders are strictly 4.8, or whether there were any customizations being done to the files by the Dev team.
If you have any documentation regarding the current status of customization under L10N or even cross-compatibility between client versions, it would be a huge help.
(it would also enable me to update the universal Japanese Voice Pack)

When I find the right files and successfully test them, I would then give them to you so you can offer the languages through the AAC Launcher.
Should the Launcher check for modifications in L10N and block any unsupported language as a result, please also let me know.

Thanks in advance and best regards,
Mystia