The target categories theat translator added or adapted from source article and decided to keep for publishing are never saved in back-end database. So, So when a translation is restored, these edits in target categories are lost. This was not a big problem in CX1, This was not a big problem in CX1 since it was only automatic adaptation of categories and no feature to add/edit categories.
In CX2, if not immediately, we willwe have these features and there should be a way to keep them between translation sessions. We can consider this as a metadata of an article to publish.
 Decide and design the newx] Reuse existing **cx_corpora** table for saving this informto store categories metadata about draft translation. Consider if there are usecases that we can merge with this and make the table more generic?Use special value for section id to distinguish categories from other translation data stored in **cx_corpora** table
[x] Develop the API, PHP classes to use the new table
[x] Translation restore should fetch this data
[x] Publishing should use the categories
[x] Any edits (add, remove, reorder) in the categories collection should get auto saved just like with any other translation section