Just today I had this issue that the Bilingual Engineering step for some of my languages was finished, but for others it wasn't. However, it wasn't possible for the translators to start working on the finished languages already - Trados wouldn't let me push only some of the languages into the Translation stage. I had to wait until Bilingual Engineering was finished for all languages.
I think this doesn't make sense at all and is counterproductive to the agility of Trados workflows. The whole point of an agile, dynamic project is that it should be possible to have different languages in different stages. It makes no sense that prepro must be finished for all languages before translation can begin.
Can you please fix this?