I'm in the process of printing this now, I have my first Merlin hotend fitted up nicely. Waiting for the fan cowl to finish printing.
I figured I'd add a photo without the fans so users can see how the unit works internally and that Merlin hotends fit just as well as the RRD Hexagon heads.
I personally am not using the "Wind sheild" (plaque_double_extrudeur.STL) as it doesnt appear to fit with the Merlin hotends. I may remix a new version to suit soon.
One thing I've noticed is that the torque from the screws can place skew on the hotends, I've found doing them up till snug and adjusting the angle by backing off seems to work well