Are they really called antenae? I just called them that because they look like bugs antennas. I have seen a picture where one line goes to it, but I don't know where it goes from there.
Nope. Just boomkins. The line that goes to it (from the bottom corner of the fores'l) Is run through a block hanging from underneath it to right in front of the cathead and then onto a pin or cleat on the inside of the bulwarks.
EDIT:
Ok, I just had a look at both versions in TOOL. COAS has an extra sail locator that tells a sail how far it can bulge out with the wind. With the rearmost heads'l it is set to zero. On the others one is set slightly to port and the other slightly to starboard. That is the biggest difference between
the two versions of those sails. Does one behave better than the others?
I think if we added extra locators like those we could get that annoying arch in the sails to look more natural. At least for CoAS.
EDIT II: There should be an obnoxiously long pennant on the mainmast, upwards of forty feet even.