Misalignment between meshes used in landscape spline segments

When using a landscape spline with multiple segments, there can be misalignment between spline segments when the tangent length of segments are too short, causing visual seams between meshes that should be expected to tile perfectly.
This happens when using either the default plane or with a custom subdivided plane.

1. Download and extract the "SplineGapRepro2" project from the URL attached to this ticket.
2. Open the project and load the "SplineGapRepro2" map.
3. Zoom in close to between the two segments of the landscape spline, and observe that there is an overlap/misalignment between the two segments.
4. Change to landscape edit mode -> manage -> splines, select a segment and then pull the tangent control to be longer. Observe that this reduces the misalignment, though small gaps are still present.