Keepaway

I find lockout lines strange, and struggle to develop intuition about them. They were launched with a packet full of puzzles, and I think I solved the the dozenth with the same timid squint as the first. Still, I think this puzzle might help, relying as it does on cages.

Rules:
Normal Sudoku rules apply.
Digits within cages sum to the total in the top left corner of the cage.
All lines are lockout lines. Digits along a blue lockout line are NOT between nor equal to the digits in the diamond ends of the line segment, and may repeat if allowed by other rules. Digits in diamonds for a given line segment have a difference of at least 4.

Estimated difficulty: 1.5 out of 5