You can manipulate and adjust the wall shape, including changing the profile, making holes, creating cutouts, and bulging the wall. The specific steps are as follows:

Create concave walls, through-wall holes, and bulging walls:
In the 2D interface, select the wall you want to adjust. In the tool panel that appears, choose "Shape editing".

Switch to the 3D interface and draw any shape using the "Rectangular" or "Draw" tools.

Select the shape you just drew. In the properties panel that appears on the right side of the interface, choose "Indentation" if you want it to be concave (enter a value smaller than the wall thickness) or to make a hole (enter a value larger than the wall thickness). Choose "Bulge" if you want it to protrude (enter the desired value for how far it should bulge out from the wall).

Click "Complete" to finish, and return to the design interface.