Because Feng Yuan mentioned in advance that the experiment had the potential for loss of control, Maomu City did not directly allocate an initial training area for Feng Yuan. Instead, they carved out a section several layers apart for him to use for training.
Although both are in the Data City, there are special space barriers between different layers. Although not absolutely foolproof, most of the time, an ultimate move losing control won't breach the layer barriers and affect other layers.
There's no alternative, even now quite a few people still live in the Data City. Even though the Temple's shelter has been deployed, the situation outside remains uncertain. For those with insufficient Beastmaster abilities, living outside still carries risks.
