How about a 30×30 hall pillar?

Of course. The entrance hall is usually the main entrance and exit of the house, so the column size of the entrance hall also needs to consider the space occupation factor. The 30*30 size columns are relatively small, which can be better integrated into the overall design of the hall and will not take up too much space. It can also provide enough cross-sectional area to bear the weight of the hall roof and maintain the stability of the structure.