Hi Karl,
Are you sure you're conforming to the SCTableViewModelDataSource protocol? Please note that tableViewModel:commitEditingStyle:forRowAtIndexPath: method belongs to that protocol, and not the SCTableViewModelDelegate protocol. Also, I notice that you have misspelled the method name as "onRowAtIndexPath" instead of "forRowAtIndexPath", this could also be the source of the problem.
Please tell me if the above fixes your issue.
(BTW, yes, [self.tableView setEditing:TRUE] is the correct way to go

)