sabinajiles
I agree with what you are saying, but I would add, with an inline you can or will could see this gas cutting on the breech plug nose. If you use the same breech plug for the life of the gun it might really become evident. I am making an attempt to change to new breech plugs every couple of years.
One of the reasons claimed for the now famous Toby Bridges Savage failure was gas cutting. Bridges had fired a tremendous amount of rounds from this paticular Savage, he also claims that the breech plug design aids in this cutting. In the case of an inline breech plug if the gases do not get stopped at the face of the breech plug and the rear of the barrel cutting can be increased along the threads of the breech area - the plug and the breech area. This normally a long and miserable time period but the cutting does happen. The greater the pressure and temperature the more this gas cutting is accelerated.
I am really thinking the majority of us will never shoot one gun enough to be overly concerned about this problem. Hotter powders and magnum loads can accelerate this process - but again it will take a lot of bangs.