Had the same scenario, and it appears to have been resolved since 2016.2
Here you can see the french "field" (I only enabled the french translation, so the others don't appear but should in your case).
Alternate method could be to create temp fields on the object and create a sql trigger to copy the values to the appropriate field on insert.
Thanks a lot for your feedback.
How did you enable the french language field? Is it possible to enable the other language fields such as german for example?