WoWInterface - Portrait(Border) Target/Focus

Hello,

so I noticed that some portraits look a bit off since they dont have real borders.

They are just cut circles and it can look weird for some previews like in this example.

So I want to create borders around them like this.

I tried to set up a black border around the target/focus portraits but I have issues with the frame layers.

If I choose low strata it will hide behind the portrait and with anything higher it will stay infront but also infront of the Target/Focus-TextureFrame:

like Here.

WeakAuras doesn't seem to be a good solution for this so I would need some help with lua.

Is it possible to do something like this so the border just sticks/anchored on the portrait without moving infront (other frames) or behind it (portrait)?

some scuffed example:

Code:

local function SetPortraitTexture (portrait, unit)

        if UnitIsUnit (unit, 'target' 'focus') and portrait then

                portrait:SetBackdrop("Interface\\TargetingFrame\\Ring")

        end

end

Any help is much appreciated. :)