In this example, I used a simple plane instead of a cube, I unchecked “Receive Decals” on the skeletal mesh and used SceneTexture:decalmask to better define where the blur is applied.
And it works but the problem is that I can’t get rid of the “blurry halo” around the character:
Such a shame I can’t exclude the character from beeing affected by depth of field, as meshes with translucent materials can be.
Or is there an option here?