Spline-generated wall doesn't have clean cut corners

I construct a building wall with a spline of 4 points to make a rectangle, but the edges are jaggered rather than a clean cut 90 degree angle.

Each wall segment is a Spline mesh, using a rectangle static mesh.

Is there any way I can tell the spline to position the meshes with a clear 90 degree angle?

At spline points, an additional static mesh (pillar or column) is usually created to hide these nuances.

But you can also offset the corner point of the spline mesh creation from the spline point in the direction opposite to the next point, by a distance of half the width of the wall.

But in this case, artifacts will most likely arise due to the overlap of two walls, and you will also have to use a wall with a 45-degree beveled angle.

I might go with a pillar, thank you!