OneWorld Accounts > For Bank and Credit Card Account types > system will not respect Include Children checkbox = T.
Bank Accounts and Credit Card Accounts must be restricted to a single Subsidiary, hence will not apply changes you make in CSV import.
If you create a new Bank / Credit Card Account > mark Include Children checkbox > system will prompt 'Bank Accounts and Credit Card Accounts must be restricted to a single Subsidiary'.
For Bank / Credit Card Accounts created through CSV > system will let you mark the Include Children checkbox and Save. However, system will disregard the change.
Pull up the same Bank / Credit Card Account > notice that Include Children checkbox is still not marked.