I wonder what the effect might be if the photographer used the approach of many painters who make prints: One signature on the original work, reproduced in the print, then hand-sign another signature on the print?
I print my name in Trajan Pro at the lower right in a color close to whatever is underneath, but just enough brighter for visibility, the total length of my name about 0.9 inches long. If the image there is highly textural I sometimes subtly darken the highlight areas right underneath with the Burn tool. Then I sign with the the Micron pen just above. Even if it's a black signature over some really dark stuff the signature can nevertheless be found with a bit of effort, it's just above the easier to find printed one.
Should mention that I also tried India Ink technical pens. Can't recommend them...
1. the coatings on inkjet papers tend to grab the pen and prevent a flowing signature and
2. the metallic tips tear up the coatings slightly which causes clogs. Lost a few prints to botched signatures this way.
3. they still leak just like they always did.
OTOH the Micron pens always flow nicely, but don't forget to exercise them slightly before signing.