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The ML hack works but an admin must understand that this is a heavy duty hack and must be done carefully.
I think it is time to offer other language solutions for balance and for admins that might not need the full featured ML hack. With multilanguages you have to pay more attention to things like caching.
There is a very old language switching module floating around. It leverages the core language switching abilities and a good alternative if translating content isn't the most required feature. Switching just the core and a module's language is often very helpful. You can do tricks with the $xoops_langcode variable for specific content translation.
If there is interest I can bundle my tweak of the very simple lang switcher. I use it on my site and has been stable.