Menu flyout blocked when within layout

When using a full-page layout.
When having a flyout-menu in the west position (left position).
The flyout is blocked by the width of the left layout border (the border between the left/west and center positions).
This feels unnatural.
As a user I would expect the flyout to overlap the border into the center content area.
I wouldn't feel that I should have to widen the left layout to accommodate all the possible flyout widths.
From a user perspective, the menu to be functional should occupy minimal width by default - just the width of the primary menu items.

use css tricks like overflow to accomodate for this

[optimus.prime]

See complex layout demo.

Thank you for the quick help - I see that in the complex layout demo source that 'overflow' is used to allow the menu to overflow the top layout.
That is exactly the desired behavior.
Thanks