The twelve inch support evidently qualifies as wall space, requiring a receptacle. But I found out this support is like two 4x4's with a metal stack pipe in the middle, with only inch and half clearance in front of the pipe - space for cable but not for a standard box.
I was looking for a shallow box with an expanded part sticking out that would look ok in a kitchen. Couldn't find one.
There is sufficient depth and width on the left and right sides, but the trim board will be interrupted by the face plates.
Are there any other options?
It could be worse, if the support wall is brick or something else that has no internal space. Would you need to utilize a popular brand of surface wiring?