More leash failures

I have often wondered why we don't use leashes like a kite quick release leash. They must surely be far stronger than a conventional surfski leash,  designed as they are to take the load of a kite. 
Of course kitesurfers attach these to their harnesses so that would still leave the point of attachment to the leg/body as a potentially weak point,  but this could be resolved surely?

One common problem I have had with velcro is re-closing it when it is wet. If you wrap your leash for some reason around yourself or your boat and need to detach and reattach your velcro on the water, my experience is that the velcro closure is not nearly as reliable or strong when reattached wet. Needing to reattach is particularly common for me with my OC1 because I often remount with my leash wrapped around my canoe.

So I no longer use velcro with any leash. I now use an NRS quick release (could call it "releash") belt from their SUP leashes which I use with one of the surfski leg leashes. If I also want relatively easy reattachment at the other end of my leash I use a light weight locking carabiner  that is not rated for climbing but still good for 2500 lbs. I do not use any kind of link that has a gate that can somehow be hit and opened unintentionally.

The NRS belt has some potential for inadvertent opening because it relies on a camming buckle - although the action it would take to accidentally open it seems very unlikely in my experience of ski and OC flips - that is  a valid concern when you are weighing lifesaving equipment reliability. But it is not necessarily easy to open the belt even intentionally, particularly if you remove the ball that is strung through the buckle for easier grabbing and opening. I personally trust this belt for my use far more than I trust velcro.

I attach my waist leash behind me so it has the added benefit of not getting in my way at all while paddling. So far I have had boats where there were already anchor points behind the seat to use for this attachment (or the rear iako of my OC1). But obviously this would be an issue or would require an adjustment for boats that have no built-in behind the seat anchor points.

Can't revive this topic often enough...
My leash-break adventure happened yesterday ("have you had yours yet?"). Got caught by a breaking wave going around a point. Had decided not to unclip (don't ask) and miscalculated. Nothing big and not a whole lot of power. Of course the boat went sideways and as I braced for getting pulled the leash just went pop. Fortunately the boat washed up on a sandy beach and I could swim in (took a while 'cause it was further out).
I'm not sure whether to be happy or upset about the leash failure. Given the outcome it may have spared me injury or an unpleasant dragging through the water. But if this had happened out in the open ocean due to a wave breaking on me it would have been not a good thing at all.
After pondering this for a bit I decided that I shouldn't focus on the leash but rather on the attachment point. It doesn't seem realistic to expect having a leash that always holds right up to the point where serious injury would occur and then releases. So I'm digging out threads about rear attachment schemes...
Pics of broken leash and intact one where I removed the shrink tube to see how the two pieces are knotted together.