Private brainstorming facilitates mediation and diplomacy
Offer more advanced functionality.
For example, there could be private problem-solving sessions in sensitive situations such as conflict resolution and international diplomacy.
There could be software-mediated private brainstorming where algorithms synthesize ideas and try to find common ground, while individual participants do not access or know the main thread of progression, but only their own experience and what is mediated in response.
All positions could be encoded and logged to blockchains with time-date stamping, where contents are confirmed but kept private by running a hashing algorithm run over them (proof-of-existence functionality).