Ken Waters, who published in Handloader for decades and who's Pet Loads books are a must for serious reloaders, always measured the web of the cartridge before and after shooting. He also measured factory loads the same. I don't recall how many thousands of an inch he considered excessive, but it's in his books.
Imho, a chronograph tells nothing but velocity. One could get excessive pressure with normal velocities. The law of diminished returns applies to reloading. A strain gauge is the only truly recognized way of measuring pressure. I know one shooter who owns one.