I spoke to the PO and he says he used the winches for the spinnaker (i have them on both sides). But that means that the big winches on the coamings are used for the jib sheets after all. I guess the biggger blocks on the rearmost tracks (halfway along the coamings) are only used for the large Genoa then...

Good to learn that I won't use them for the halyards after all.