So, what Fates harvest does (and what we are using a version of for Miami) is both Xp and Arcade Tickets. Xp has a weekly cap and it's fairly easy to reach with minimal staff interference. Once said cap is reached for the week, you instead earn an alternate currency that can be used for a variety of other things.
I like this, because well, i've had more than a little experience with XP going awry. When people go 'Oh Wretched, it's only a +1, Its just another +1, it's just another +1. And then one PC has 1500 xp because headstaff gets burnout and another staffer decides to do all the XP jobs for members of their own IC RP group and it derails the entire games XP system.
Not that i'm bitter.
I am generally with the 'I am in this hobby to be in this hobby' and I really hate xp based incentives, because it always starts out as 'oh its just a minor thing'. and then 'well you allowed that minor thing, why not this minor thing'.
So, alternative currency, maybe use it to play an antagonist for a specific time and plotr, to skip[ PRP justifications, to create a side economy of trifles and gewgaws and other limited one use items from across the spheres. Cash in for a personal plot about your past. Theres a lot of ways to use an alternate currency that isnt directly related to inflating your character's stats more.