you’ll have to cull using something like ClosestPt, or extrude and intersect. Since project goes in 2 directions always, the curves on the opposite side will also get projected.
I have done it for multiple branches, but I am only having problems with this specific branch. The other branches work flawlessly with just a single projection.
But I think I know what you mean now. The other surfaces I have are slightly angled so the projection isn’t reaching the other side.