You can determine the shape of one edge of a stair run that includes flights and landings for straight, U-shaped, multi-landing, or spiral stairs.
The size of the landing must be adjusted to prevent overlapping treads when the inner edge of a stair is projected to a profile that lies outside the original stair. The initial size of the landing is determined by projecting the diagonal of the original landing to the profile.
Using grips to change a stair landing width
Pushing one tread into the landing with its grip forces the landing to lengthen in the other direction. Pulling one tread away from the landing does not affect the other end of the landing. The stair is lengthened at its top to accommodate the larger landing. You can modify the length with the top and bottom grips, at the end of the stair walking path.