Things I know: Nylon as it ages and some other hard plastics get extra dehydrated as they age and get more brittle as a consequence, also numerous deformations build up causing stress failure. Things I should do: boil a big pot of water and drop all my hsf brackets and retention clips in it until it cools, to help rehydrate them and anneal stress. Next time I will remember this: when another clip or bracket breaks 🤣