But then again, I think maybe there is a subtle difference in nuance. To me, the ISU's wording "a maximum of ten per cent" is sort of leaning in the direction, "Obviously the national federation will steal as much as they can, but we are here to tell you that you can't take more than ten percent."
Whereas if you say "up to ten percent" that sort of puts the default floor at zero. And then you are allowed to dip into the pot, but you have to stop dipping when you get to ten per cent. Something like that.
Oh well. Never mind.