Correct, each object is on a separate timeline for purposes of operational transform. If both clients are connected at the time the changes are made, then it shouldnt be possible to see the second change before the first. We keep an ordered history of all changes to all objects, though for efficiency, if a client that wasn't present when changes were initially made syncs, changes to multiple objects may appear in a different order. For example, a modification to object A, then object B, then object A again, would appear in the correct order for all clients when those changes are made. If a different client then syncs and asks for what's changed, we may group the two changes to object A such that there would appear to be two changes, a change to B then a change to A.

There is currently limited support for keeping a subset of data synchronized (we have plans to improve this) - if you're using the client libraries in an app, we've focused on supporting the common case of keeping all the data per bucket for a user synced. In the case of keeping all data mirrored to a backend, we provide an endpoint per bucket that you can listen to all changes for all users so you can keep the entire data store synchronized.