It'd be nice if the post went into how conflict resolution will (?) work because that's the hard part here and the main selling point imo.
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How you reconcile many copies of the same record could depend on time of action, server location, authority level of the user, causality between certain business events, enabled account features, prior phase of the moon, etc.
Whether or not offline sync can even work is very much a domain specific concern. You need to talk to the business about the pros & cons first. For example, they might not like the semantics regarding merchant terminals and offline processing. I can already hear the "what if the terminal never comes back online?" afternoon meeting arising out of that one.