WhyN0t
Master Sergeant
It's the same xp. But you lose motivation somehow faster with 15/30 min compared to 1 hour. You get 1 hour with 100% motivation while you get 30 min with 100% motivation and 30 min with 98% motivation etc. You got the point. It's worth spamming 15 min for farming event coins (pretzels, hearts etc.)