I'd like to see double rifles with such a mechanism. Cocked on opening automatically. Some sort of triggervsafetyy or better cocking release prevention safety. But allow hammers to be unlocked manually.

Nothing different to internal automatic cocking except as exposed can be manually uncocked.

Carrying around a cocked double gun all day with the safety on,it's far more reassuring to be able to uncock it. And also avoid these annoying shoots where the cotton wool organisers expect guns to always be carried broken.

Of course a gun like the Krieghof has a safety de-cocker which uncocks and re-cocks the internal hammers. Pity the Krieghof guns are not styled more classicly