Informacam has a similar “chain of custody” goal but was developed for existing devices. Guardian Project was involved with CameraV, the android version for mobile devices. It looks like Proofmode is now the active project & it’s available for ios as well as android. https://proofmode.org/
instead of the majority of users having to create blocks (multiple opt-outs) couldn’t this be set up so users that want bot posts sign up or opt-in somehow?