The proposal for the logo's on the sails are only to avoid wildly varying ways of stickering up the sail that could lead to confusion. Apart from that I don't see a point in ruling on the logo's other then specifying the shape and single colour use. So it is your choice wether you put it on the hull or sails. If you do put is on the sails than it is prefered that you do so in the bottom part of the sail. That is it.
Robi is right that everybody is welcomed to use his or her personal freedom within the rules.
In short ; the proposal rule number 5 applies :"-5- markings on other parts than sails are left largely open as long as points -3- and -4- are satisfied"
Regards.
Wouter