[email protected] https://github.com/3Dartmodeling/surface-mesh-blender

Yes future licenses are included.

Auto-update only regenerates the panels whose boundary curves actually changed, and uses the lower Preview resolution while you're editing live. Switch to Generate / Generate All at your full Resolution (export) setting when you're ready for final quality.

Yes. It's a general Coons patch surfacing tool — car body modeling is the workflow it's tuned for (panel naming, Auto-fix, the curve tools), but it works for any surface you can describe with a 4-curve boundary network.

Don't apply the Mirror modifier through Blender's regular Object → Apply. Surface Mesh regenerates the panel mesh live from the curves, and a normal Apply removes the modifier — so the next regeneration has nothing left to mirror, and the mirrored half gets silently overwritten. Use the add-on's own Apply Mirror (in place) button instead: it bakes the same result but marks the panel so Generate/Auto-update leave it alone afterward. Un-apply reverts it any time.

That means the 4 boundary curves don't currently agree on direction or role. Click Auto-fix Curve Directions on that panel — it checks every combination automatically, including the case where a curve was assigned to the wrong side entirely (an easy mistake to make on a mirrored panel).

No — Bezier curves only. Convert any NURBS curves to Bezier before using them with Surface Mesh.