Can't find much related to rake of the spreaders.

I've noticed a few Mozzies of varying ages with masts with swept back spreaders pretty much in line with the rear edge of the mast and was wondering what benefits this has particularly when so much forward mast bend is induced with modern sails and downhaul tension. Is it better to have the spreaders raked back or better to have them set at 90 degrees to the mast ?

If anyone has has thoughts on the issue I'd appreciate them.

Regards,

Peter