Projected Sweep breaks when pulling surface

I’ve got a couple questions on Iteration 3 of this GH dfinition I’m working on.

The first is I’ve created lines at specific intervals and projected them onto a surface. I’ve swept another geometry along that surface with the thought that If I curve my panel the sweep will curve with it. When I pull my curves to modify my surface some sweeps do stay and some disappear.

Another question is I’ve created new planes to keep my geometry corners along by bottom rail. But my Z vector doesn’t follow the angle of the projected curve, I tried “perp frame” but it ended up twisting the plane out of alignment with my base curve (the one along X @ 0 in Z). The point of this is I would like my geometry to start out perpendicular to my sweep.

Any thoughts?

ParaCurved Panels.3dm (41.5 KB)
ParaCurved (21.3 KB)

Edit: It seems strange, the sweep brakes depending on how I move my curves. If I take the projected curve which is essentially the same curve and reproject it onto the surface then it seems to work? @DavidRutten Am I using this incorrectly? See two pictures below.