I would just love to read the PF's insurance policy requirements. Or not. My guess is that nothing has ever gone awry and so the status quo is fine in their eyes. Not an uncommon behavior but Lord help the fool when the s**t hits the fan.
I appreciate the insurance point, but many stamps entrusted to PF are not fungible. If I was the owner of US C3a position 49, and Mr. Kaufmann was mugged at 125th St on the Metro North New Haven Line as he headed home to Connecticut or wherever to "study it further," I wouldn't want an insurance check, I would want that stamp. Regular, or at least any, communication would help as well ... they had postcards in the "old world," after all.