Hi Gérald, thank you for responding to my question.

Even if true U-V-W orientation would theoretically be ideal, a VWD gizmo to locally guide the direction of parameters would be very welcome, not only for the split flexibility/rigidity settings of a selection of vertices, but also for the controlled expansion/contraction of such a selection.

It would be absolutely wonderful if you could (and would) design and program such a control widget for VWD!

Cheers!

Erik