It maybe works in theory, yet no real studies by the correct agencies to allow acceptance of that method either.
It seems the only prohibition or difficulty would be in computing the AWG size of the remaining strands. There is no requirement to use standard AWG sizes or prohibition on reducing a conductor in size. I see no issue calculating this in the field. granted it could be difficult with compressed conductors where the strands are oddly shaped, but for compact conductors there is essentially zero gaps between strands so you can easily compute the new size if a "ring' is removed. Yes removing a partial "ring" would bring in you into difficult to calculate territory.