The end goal is to help people know what to look for to source parts, or to finish clone builds, or just to know something cool about something they might be interested in.
In reality, having an off angle staked gas key isn't much of a concrete manufacture marking. Any other company may do the same. That alone wouldn't signify a CC or D manufactured carrier. A roll mark would.
As it happens, the staking marks are a manufacturing mark. During early phases of SARP I, Diemaco was getting up to speed on M16 manufacture and developing the Diemaco process for forging barrels. The initial carriers were C marked Colt's for trials. Interestingly, the few that were used are still in service and can be found in CF weapons to this day. The first pre-production carriers were Colt's parts, assembled in Canada. They were offset staked to differentiate where assembly occurred. Early low rate production was Diemaco improved carriers with Colt's keys. Then finally all Diemaco parts, all assembled in Canada. The offset staking was kept to identify Canadian assembled carriers for cooperative various projects. No Diemaco export carriers were ever made with no marks, and all were offset staked. I've never sen another manufacturer use offset staking. Diemaco carriers were all D marked and were switched to CC marks after the company was re-named.