I'm pretty sure it could be done tho, lets say in CurseClient/Minion you set the language you want to use your addons, then the client comments out every other language files from the toc or even don't even download those files, just like how the nolib strip works:
Toc Code:
#@no-lib-strip@
# embeds.xml
#@end-no-lib-strip@
It would not just speed up the download processes and save a fuckloads of traffic, but remove a lot of clutter and even slightly speed up the addon loading process.