It,s normal to have some looseness in the luff tube on wide sleeve sails, if it were drum tight the sail would not rotate. However if it is excessive it may indicate that you need to add cam spacers. I would try a spacer, check the rotation, you may even need 2 . It is a trade off with rotation, so just get the tension you like. Speed sailors who don't care if the rotation is stiff will pack the cams quite hard, but for general sailing leave it a bit looser.