If you ask any feng shui practitioner what would be the best facing for period 9, almost all of them would probably answer with it depends.
And rightly so.
This is because in the context of such a question, the assumption is that the asker is a homeowner who wants to benefit from good feng shui. And the answer to this eternal question is not a matter of what direction his or her residence is facing.
It also heavily depends on the floorplan, interiors, and external land forms, etc.
There is also the small matter of which feng shui school of thought is being applied. However, when we say period 9, the context is most probably flying stars feng shui as the periods is a fundamental law of Xuan Kong feng shui.