Lack of new challenges

I think that there is something to be said about the lack of new challenges every day. There are definitely other aspects of the feature that needs addressing but I really think there should either be faster refreshes or a way to get new challenges consistently once you have finished all of them. I quite enjoy doing the challenges - especially to get XP etc - but I almost always find myself finishing every challenge besides the amateur ones and not having any other decent way to get XP. I've been playing skate a lot recently and it's a shame that there aren't more to access - all my areas are level 7 or higher and I'm still lacking new challenges.