On my old L3000dt I always felt like the turnbuckles were a week point. I bent several. Enough that I kept 2 spare sets around at all times. The concept was fine I guess, but in the field they didn’t hold up to bushogging, tilling and blading very well. Tended to bend.
I did learn finally that keeping them as tight as possible- for me seemed to help. The exception being mold board plowing as another post mentiond. Otherwise if I left sway in them it seemed like they bent more often.