SubD extrusion not possible

[davide76]

I don’t know if it’s a bug:
It is not possible to extrude (with gumball) two non-consequent faces and with a vertex in common.

(Rhino 7 - SR16).

[diff-arch]

It would produce a bad, non-manifold geometry.

[davide76]

That is fine. So it’s not a bug.
Thanks