1. happens only once per 24-hour period.

2. means that each "system" (CRM/Books) is storing its own record (account or contact) and that I must choose "Clone, Overwrite, Skip" to resolve a duplicate.

3. There is no ability to merge two records on a field-by-field basis.

However, "invoices" can exist in CRM or Books or Both. Further, in CRM I can choose to create a "Books" invoice which is different than a "CRM" invoice but if I create a "Books" invoice that is is a single row in a table that is shared between both systems and that no sync is necessary.

Do I understand correctly?