I've had a 200-500 for almost 2 years and never once encountered anything like what you're describing.

with the first lens, I had the strap entirely connected to the camera without the lens foot, I understand now this may have put a lot of undue pressure on the on contacts. With the second lens I used the lens foot but still had one side of the strap attached to the camera.

I personally would strongly suspect this had something to do with it. The 200-500 may not be as big as an f/4 prime, but it's still a beast. You really need to carry your setup by the tripod foot/collar.

Point of interest: the tripod food and lens collar that come on the lens are dogshit. I'm not going to get into my feelings about Nikon selling supertele lenses that cost thousands of dollars and putting tripod feet on them that aren't natively Arca-Swiss compatible, but suffice to say that I'm not a fan of it. However, the feet are also too short in my opinion, and they don't feel sturdy enough to me.

On both my 200-500mm and now my 500PF, I've upgraded these pieces.

On the 200-500, I am a massive fan of the Kirk Photo NC-200-500V3. It's a complete upgrade in every single way. Gives you a much better handle to carry the lens by, gives you native Arca-Swiss compatibility, has a QD attachment point, and the huge knurled knob is so much easier to use, especially with gloves, so you can actually lock down the lens securely.

I absolutely recommend one of these to anyone with the 200-500mm. I know it's expensive, but for me it was an absolute must have. I actually started with the V2 version and when I saw that the V3 was available (with the added QD slot) I bought it at full price.

If you're wondering about the QD thing, it's a slot that accepts hardware commonly used on rifle slings. That might sound odd, but I'm absolutely convinced that this Magpul rifle sling makes the best camera strap that I've seen so far. A big reason for this is that this sling is designed to connect to a single point on a rifle camera, so you can connect it to your Kirk lens foot and support the whole system from that one point. It allows for free rotation without the strap getting twisted, it allows a great range of motion so you can raise and lower the camera without the lens getting in the way, and of course since QD hardware is designed for carrying rifles into combat zones, it's highly durable and IMO more trustworthy than a Peak Design clip. I would generally suggest going with the Grey or Green colors as they look a bit less...tactical...than the black or tan.

After carrying my 200-500mm with this setup for nearly 2 years I bought the 500mm PF and before it even shipped I bought the ProMediaGear PXLN1QD Foot to replace the OEM one because I refuse to use a tele lens that can't accept QD hardware and isn't Arca-Swiss compatible.

This got way longer than I intended but I just wanted to share my thoughts and what worked for me. I do fully understand your love for the lens. But the collar and foot are IMO the biggest weakness ergonomically speaking.