How much outhaul do you have on? Just prior to putting tension on the downhaul I put tension on the outhaul, a couple of cms more than I am planning to sail with. This causes the mast to bend more than required and make the downhaul a lot easier to pull down.
The biggest sail that I use in an old 8.8 NP RX1 (4 cams). I mainly use cleat handle or sometimes the harness hook (when I cannot find the handle

), both are suitable to get more than enough donwhaul on.
I am tempted to save up a few pennies for North Power XT though