I just finished this on my priest Radrohn, with the last goal being the "ride +30km/h" one. Somehow, it got credited 5 times, with all the rewards.
I can give further details on what I did exactly but I feel like being too verbose with it publicly just invites someone to try and exploit this, so I'll withhold it until a dev wants to get Pm'ed about it or say it's fine to post here.
Now I also have to deal with the duplicate rewards. Should I file a ticket to have a GM remove the 4 superfluous affinity tokens (They're nodrop, obviously.) from my inventory and subtract 2h of sleep bonus? (Since I'm full on it now, though the goal should just give 3h)