I believe if your primarily looking to speed donning or removal any can work well. I’ll assume your talking your AO in Texas?
In extreme cold synthetic hardware can become brittle and metal can become wet from temperature warm inside to cold outside and freeze.
Probably not cold enough in your area to be an issue, but mentioned for others.
If possible water entry is an issue where you need to drop carrier to prevent drowning, metal buckles if shut accidentally over even a small piece of webbing can bind when water expands webbing.
I have seen this in the helo dunker during training. The metal safety belt was accidentally closed over a small piece of webbing from a survival vest and when water absorbed in the webbing resulting in trapping individual. Even a safety diver couldn’t get buckle to release. Fortunately the whole helo dunker was brought up with individual hanging upside down and diver still struggling to unfasten buckle.
Never seen the need for this myself; I assume you are looking from a medical perspective? I have the first spear AAC with tubes. Best PC out there. Tubes attach the cummerbund and shoulder straps.
If you need to get under the plates to do a check during tactical field care, and you are still having to evacuate under potential fire, popping the first spear tubes off and back on is practical, versus a no-going-back dump system that some PCs have. Thus you don’t have to deprive the casualty of all protection