How do I apply a sheared gradient without modifying the objects it's applied to?

[vitaprimo]

I want to apply a linear gradient with a parallel axis. These I've only gotten them exclusively by accident, never on purpose, I need them now though but the drawing is done, isometric, to scale, very easy to screw up.

 

In the help the only guidance is that I skew the thing to get it, but I'd rather avoid that — even with the transform panel's precision — unless there's absolutely no other option.

This is the one I need, BTW:
(well, sort of; I need to apply it to open strokes)

Can you share the secret, please? I promise I won't tell.

This is in Designer.

[NotMyFault]

There is no way, except applying shear to a layer, adding gradient, modifying shear angle of gradient, and resetting shear of layer. The shear capability seems to be bound to the layer, not to the gradient. Saving gradient as style does not include shear.