Re: Proposal to automatically make the owner/user of an accepted socket the current process

 Have you considered making this an "opt-in" with a setsockopt() to enable/disable the change?
And maybe a sysctl to set the system-wide default for processes which don't explicitly set that setsockopt()? Or does that "go without saying"?

if nothing else, that lets the adventurous experiment with the change, for specific (modified and recompiled) services, without affecting anything else.