Swept Back Spreaders
Is this a new boat? Even though this is a masthead rig, with the swept back spreaders there will be a certain amount of mast bend caused by spreader tension. When looking at the rig, the swept back spreaders are pushing the mast forward, hence the bend. Since this is a masthead rig the backstay shouldn't have a significant effect on mast bend. Backstay tension will take some of the sag out of the forestay so there is some minor fore-and-aft movement of the mast but this is very small. An increase in the backstay tension is really valuable when going to weather in a breeze in order to take the fullness or draft out of the jib. The good part about not having the backstay tension loose to the point the forestay flops around is the possibility of component failure due to work-hardning of the metals is less.