Broadcast
Like Mode 1's parallel fan-out, but with the accumulated transcript prepended. All N brains run in parallel. asyncio.gather over the per-brain calls.
Point
One brain gets the turn. Optionally Dad adds a comment. The targeted brain receives the transcript + Dad's comment + 'Now you respond.' Other brains hear about it next round when the transcript updates.
Point-only
The turn is passed silently — 'Dad stayed silent. The next move is yours.' Useful for letting a council unfold without continuous Dad commentary.
The principle: Three turn patterns, all built on the same mechanism (transcript prefix + 1:1 turn). The patterns are usage conventions, not separate code paths.