Planar Surface fails to extend past small distances?

[Intuos]

I’m trying to extend a surface edge from a planar surface constructed from an offset polyline.
Any idea why the extension distance can only be this short?

Extend Surface.3dm (42.1 KB)

[Rhino_Bulgaria (Bobi)]

Looks super weird. This bug typically happens on degree 2 cylinders or ball objects, sometimes on a higher degree freeform surfaces. Is your surface completely flat and degree 1?

[Intuos]

Yes, all degree 1 and planar:

It only extends in really small increments:

[Intuos]

None of the possible suggestions in the thread below help me extend the surface.

Why does Extend Surface stop? (Can only extend in small increments.)

That’s the very definition of “back-end”. That’s because you probably mostly use Rhino. The rest of the world has quite some interesting developments if you check them out. Anyway, this is very off-topic now. Let’s save it for Rhino 9!

And since Rhino 9 is about to be here (including a Stretch command akin to AutoCad’s), could this be fixed too?

Try and extend the short ends of this surface.
Extend Surface.3dm (42.1 KB)