So, I ended up rejecting the black dial because of the defect in the marker. Since there were no more black dials in stock I took the blue instead.
Andrew (trustytime) was very helpful and fast with the switch. A perfect customer experience if you ask me. I got my watch 5 days ago. You can see the pics below.
What to say ? it's really a fantastic piece. I am admittedly a noob in the rep scene, but for having played in the past with reps from DHG or Ali, the difference in quality is astounding.
The dial color looks more black than blue to me in normal light, only under the sun you can really see the blue coming out (and the sunburst).
The slide rule alignment is nearly perfect IMO. That was very important for me and I am really happy with it.
All functions work of course but the start stop button feel a bit hard to press.
The only small issue I see is the dial is a bit "sunken" w.r.t the slide rule, as you can see in the last picture. It's more flush at the bottom. Do you think that I can open it and push the dial a bit, or it depends on the crown and there is nothing to be done ?