I think it's pertinent to point out that frame size directly correlates with weight distribution, center of gravity and potential issues potentially caused by short chainstays.

I was listening to a cycling podcast where it was mentioned that it's weird that different frame sizes have the same chainstay length. I hadn't really given it much thought but now it seems so obvious. Larger frame sizes should absolutely have longer chainstays. A taller rider is sitting more rearward of the bottom bracket than a shorter rider. To achieve the same weight distribution the chainstay would need to go back as well.

My point is: The bike in your picture is a pretty small size. It's unlikely you'd have any handling issues with rear loads even with CS length of 425mm. For a smallish frame size 425mm isn't that short of a CS. If we had more proportional wheel sizes smaller frames could have even shorter CS's.
Your stem length also doesn't seem to be all that short, which means the reach on said frame is nice and short. That in turn means more of your weight is at the front wheel which helps negate the luggage weight of the rear wheel.

I tried to use myself as an example in my earlier post, because it's really not possible to make overaching statements how short chainstays are bad for touring. It depends. And for anyone else reading this, that's the real takeaway. Make sure the weight distribution works before loading up the rear. Even a short rider may get into trouble if they're riding a really long gravel bike which forces them into using a 40mm stem, yet which still has short chainstays. A well balanced bike is likely not going to be an issue even with short chainstays.