Did all four mountains (including Splash and 7DMT twice in the same day) and got nothing 
Curious. Did you have fast passes for all three mountains?
I’m not sure if they can(/do?) track that you rode all three if you don’t have fast passes since you wouldn’t tap in.
Splash and Space (and 7DMT) have on-ride photos, so they would know you rode those. FPP for BTMR would be the only way they knew you rode that one.
Definitely curious as to how you get it. My friends and I rode all 3 (had FP+ for 2 (BTMRR and Space) and rode Splash with a super low line time) in October and I didn’t get anything.