Hi, Daniel,
What did you mean by this (because the UI model is not cleared before read).?
Can you keep two fields, one for inport UUID and one for your custom BO UUID?
After reading your custom BO with the inport UUID(BOOperation Read), you should use Condition below the read operation and check for the custom UUID if it is empty. If it is empty, then you can call a create BOOperation.
Hope this help.
Regards,
May T.