In order to increase the number of FP+ given to each guest, they would have to increase the number of FP+ available per attraction. This, in turn, would result in a ratio of FP:SB that favors FP even more than now. Eventually, they could get to the point where the ride's capacity could only handle the number of FPs given out. I doubt they would go to that extreme, which is why OP contends they cannot increase the number of FPs given to each guest. Those additional FP+s would have to come from somewhere and that somewhere would be more FP+ and less SB.
YES! this is exactly what I mean.
I'm afraid my consideration for others seems to take a slide on Sundays. I shall work on that 

