The honest way to use the Vignon marks is not to dwell on works of art that seem to prove a desired POV, but on many works that question that POV. Create a comprehensive inventory of pantokrator portraits, death portraits including epitáphios, resurrection portraits including man of sorrows depictions and lamentation scenes. This should be done without regard to the Vignon marks and other features. For each work of art try to assess geography, period and artistic style. Then inventory the features on each work and characterize them by stylization. The results might astound us.
It is time to stop proclaiming the gospel of serendipity on your blog and do the real work. In the end the Vignon marks may prove significant. I am hopeful.
Whereas I think some of the Vignon markings may be significant, I am also someone who is asking questions. This is a call for a systemized study. It sounds like a good idea but will anyone who is qualified really do it? That takes objectivity.