The accountant hub is a good idea and my suggestion is to also have a reseller hub. The reason behind this is that customers regularly need support from the reseller and the reseller needs access to their system. To move a license from a customer user to the reseller user takes a while to complete and the reseller would need to wait for a customer user to log out while the work was completed. If a reseller hub was introduce this would fit well with the current workings of the accountant hub as it would be the same idea. There will only need to be one reseller license allowable per tenant.