You're fine. That's the Stealth highback, super flat up top.
Honestly you might do with moving the heelcup back, I know it means your boot isn't centered, but they thong strap sits much better with less toe overhang.
Go ahead, drink that kool-aid.
FS: Forum Sauce 142 $200 plus shipping
FS: Flux SE30 $75 plus shipping