I had some progress but only by "voodoo programing"
I used the Blob_replace module and got the CROSSHAIR_COORDINATES for the two blobs. I was able to draw a line between the two crosshairs but I still don't get how that worked!
I used the "Display line(s)" module and selected as the Data Source: Variable
X Start = CROSSHAIR_COORDINATES
Y Start = CROSSHAIR_COORDINATES(1)
X End = 0
Y End = 0
It works but I don't get the logic in it.
I haven't managed to get the angle of this line.