Is there a rule for how positive or negative offset distances correspond to an “inward” or “outward” offset direction?
Use Dot and Cross Products VS a defined “orientation” Vector3d.
usually negativ offset leads to to inward offset and positiv to outward but it sometimes is a little buggy - ill recommend you offset curve from the pufferfish plugin its more precise and flexible
It should depend on the direction of the curve and the reference plane you’re feeding the offset curve component with.
If your inputs are consistent (curves and planes), the offset value (positive or negative) will always be in the same direction for all your inputs.
Or offset in both direction and get the longest or shortest of the two curves depending if you want outside or inside respectively (less recommended) 