Can mr Liviu make it possible to change timetable manually at the end ... I mean after having a good timetable you have the possibility to change between 2 or 3 teachers if needed !
I am sorry, but this is out of my main knowledge/experience. Unfortunately FET was designed from the start as an automatic tool, and now it is difficult to incorporate such a change.
Maybe you can use
@Volker Dirr 's TiTiTo (which is proprietary software).