Actually, CF has said he wouldn't do behind the neck pulling if he were to do it today. From talking to a couple high class (one of whom has coached multiple top 10 in the world sprint swimmers) swim coaches, weighted pull-ups are definitely tougher on the shoulders and should be avoided as a purely strength exercise (like one would use lat pulldowns for example). How much weight are you using, wsgeneral? I've done sets (usually 5-10 reps) with 45-65lbs and it was definitely tough on my shoulders. The thing was, it wasn't even max effort. I always left at least 2 reps in me on these and I still felt it in my shoulders (similar to even I was doing full dips with weight) to the point where I didn't feel comfortable increasing the weight further. While it wasn't too difficult on the muscular system, the weight felt exponentially tough on my shoulders (25lbs wasn't bad at all, 45lbs started to feel it, 65lbs it began to be an issue, etc.).
In swimmers and other overhead athletes it makes more sense as their sport places a lot of stress on the rotator cuff, but for track athletes, it shouldnt really be a HUGE concern. When do you train lat pulls or pulls for max strength? I consider pushes and pulls more auxiliary work for track athetes–yes I do go heavy and low at times, but if I am really after difficult pulls, I go single arm. I use about the same range as you for weighted pulls. I've gone as high as 85 for sets of three, and had no discomfort at all as well as 25lb for single arm pulls, but I've been doing pullups for a long time and started with jumpstretch assisted pullups which could have had a prehabilitative effect.