I do not have that specific example in my examples of signed T206 Marquard portrait poses. Having said that, I stopped cataloging new examples as carefully after 2018 -- which is when the forged T206 scandal broke -- so all that really means is that it hadn't surfaced in the hobby prior to 2018.
I think Dan's example is authentic, but I would note that it was done in the same style -- black marker/felt tip pen, somewhat sloppy, running up the right side of the card -- as the forged one that was outed on Net54 in 2018:
This would give me some pause before I purchased a similarly penned Marquard signature today. When I purchase autographs of Marquard lately, I look for "tight" examples in "confident" ballpoint or steel-tipped fountain pen:
