I found that I could half fill a textflow with plural forms and save as fuzzy, but pressing Translated seemingly has no effect.
This would be frustrating for someone who only cares about 4 out of 6 plural forms for a given string, and eventually they may fill in the last 2 to "see if it works then", but it's not good UX to allow something and fail silently.
1. Upload a document with plural forms in some source strings
2. translate that document in Arabic
3. Fill in 3 out of 6 forms for a string
4. Press Translated
Either accept the translation, disable the button, or notify the user that all targets must be completed to save.