Since spinning in one direction is a requirement, I don’t think looking at the zip and solving the chaos slot machine issue is important. (This could just resolve itself once the ‘spinning in one direction’ thing is figured out.)
If you were to ever share a zip, I’d ask you to do it publicly incase any other forum members wanted to hop in.
An idea to make that work with ‘RInterpTo’ : a way for it to reject+reroll values that would make it roll backwards. But I’d be leaning towards finding a way to use ‘Add rotation’. There’s also a ‘RotatingMovementComponent’ that can be added/controlled, but that applies to the entire BP, so a more ‘distributed’ (Each reel in a separate BP) approach would be needed.