@DanielR
Looks good the Update to 3.32 has enabled Projection to function properly across all three angled and one rounded face of the original Design.
I imagined this would be similar for the following:
The above had the mis-projected Spline removed and on running Tool > Projection again it appeared in what looks like the same place as it did first time out.
This Design was one of a few, while attempting to determine what was going on.
This is the shapr. File involved:
SplineOnAngledPlane.shapr (128 KB)