Permanent Meta bans wipe DMs, photos and shared files. For anyone handling NDA material through social platforms, that is a compliance failure waiting to happen. Here is the safer architecture.

Three private surfaces. Same zero-knowledge architecture.
A disabled Instagram is inconvenient. A disabled Instagram that took your client's confidential brief with it is a breach. Architecture, not promises, is what keeps NDA work safe.
Three private surfaces. Same zero-knowledge architecture.