I am using RBE in a multilingual Open Source project, UDIG. It is my task to add/fix the German translations.
I have currently no ideal way of finding missing German translations with RBE. The plugin marks missing translations, but they are often missing in another language except German.
Therefore I'd require one of the follwing:
(A) Allow to mark only entries as missing (yellow warning sign) that are missing in one specific language OR
(B) Allow to configure RBE to completely ignore certain languages (as if the files didn't exist)
(C) Offer a wizard (or something similar) that gives a result list with all translations missing in a specific language
(and ideally also texts that do not exist any more in the default language and are orphans in the language of interest).
I moved your request from Bugs to Feature Requests.
A workaround for your task would be to copy your default resource file and your German resource file somewhere else, and open it there. In that editor the missing translations are really missing only in German.