Some municipalities want us to define it as a polygon, but since we cannot assign a polygon, we have to convert the polygon to a column. Especially the municipality in the Altındağ district of Ankara wants this way. So you can put polygon curtain option. In addition, I made all of them polygon columns for testing purposes and I could not assign beams from column to column. In other words, there is a problem in the other columns, not the U curtains you showed me.