Important question:
Is the projection (of your points) required or are you okay mapping your surface to the target mesh (no mesh splitting)?
If not required, you can rely on MeshMap + Sporph this way:
SporphTrimmedSrf.gh (53.6 KB)
Essentially you’re transforming the untrimmed version of your ribbon surface, which then facilitates mapping your trimmed ribbon surface from base to target surface:
Same thing here, just a bit cleaner without moving the target mesh up (unless that’s important, in that case ignore):
SporphTrimmedSrf_no-move.gh (52.9 KB)
If you MUST stick to projecting + actual mesh-splitting, one option can be something like this:
