I repost my reply from this discussion. Maybe it will have a better visibility here.
I'm currently working on MDL-54731 issue.
My approach was to remove the general administration settings (submissionstatementdefault) and use strings in language packs instead. This solution works very well for a multilingual site, however the language customisation is less user-friendly (you have to use language customisation function, open pack, search the right string identifier, etc).
Another approach would be to keep current submissionstatementdefault administration settings... but definitively I don't see how to bring internalisation in this case. Maybe we can keep those settings. If these variables are empty, so we use strings in language packs. If not, we use administration setting values.
What is your opinion? Any suggestions would be appreciated.