Based on your attachment experiences with former t's, do you know what you would need from this t if you did get attached? As in, what kind of out of session contact do you think you would need? What might you need by way of reassurance from t? How much self-disclosure does he offer up? What kind of boundaries does he have? Maybe try to figure out what it is you need to make this work and then find out what your t can and cannot provide. Make sure he understands the disorganized attachment style as well before deciding what to do.