First of all some background info, I'm currently using AEM 6.1, and the classic UI.
I'm running into an issue when using the msm API. My code gets a rollout config, establishes a LiveRelationship on two pages (with deep = true), then calls RolloutManager#rollout. After doing this, I can see the cq:LiveSyncConfig node set up on the parent of the copy, with deep = true in the properties, like I would expect.
The issue is, that when done in this way, the configured RolloutConfig only executes on the parent page (despite deep being set to true). Alternatively, when I create a new live copy via the UI (new -> Live Copy via the SiteAdmin), I see the same resulting nodes in the JCR (cq:LiveSyncConfig exists only on the parent, with deep = true), but the Rollout itself also executes on the Child Pages.