During a tack the boom surprised us with a violent slam as it swung across. Our traveler cleat stripped the outer covering from the line.
Two parts to this... The slamming across of the boom in a gybe, and the line giving away (absorbing some of the force in the process) as a sacrificial lamb, saving the cleat or something else from breaking.
Dyneema would work just like wire. Zero stretch of give. Would you be willing to use wire for this task?
The line was likely chafing from previous events. It finally had enough and sacrificed itself.
I would not use dyneema in this role on your boat. You need the line to be a little forgiving. I would look to a good dacron/polyester line or back to stay-set if you prefer.