I'm currently testing the MS Custom translator using my own models through the MS Translator Hub (Azure subscription) (similar to UpLift Fragment Recall in Trados)
It works very well in Passolo using the 'Category ID' as Model identifier. The main issue is that Passolo stores the Category ID for all the lpu projects (information is stored by general settiings). So it would help a lot if we could store this information depending or subjects/domains.