Hi David,
Technically what's happening is the ACP hub intercepts all sync commands being sent by any software (ACP included) and only allows the first sync to get to the mount - taking care of any startup bias. From there, all syncs update the model. If MaxPoint is connected to the ACP hub, the exact same thing happens. If MaxPoint is connected directly to the mount, then the user has more control of what actually gets to the mount versus adding points to the model.
Jim