North 9.0 WARP with softer masts
I've purchased a second hand 2006 North 9.0 slalom WARP and I have rigged it with a compatible 520 / IMCS 32 mast.
I've noticed this sails is very physical and from recent races I came out really exhausted !
I regularly use North formula and free-race sails with their recommended masts and I valued NS sails for their soft feeling but I feel this sail (9.0) is really hard to drive & control when wind rises.
I wonder if this depends on using a compatible (maybe stiffer) mast than original 520 North (anyway, always IMCS 32).
What do you think if instead of using recommended 520 / IMCS 32 mast I will use a softer 490 mast (or a mix of 520 bottom and 490 top) ??
Thank you in advance for any help.