Command upgrade should be done by commanders. They can transmit the FO upgrading a lot more about the job, experience, tips, etc than a FO doing SFI work but with not actual experience on the job. Command is not about flying but how you manage the resources. But If it works for Ryan............ cheap for them.
it is cheaper to pay an FO to do SFI job that paying a Captain to do the real work. Training is a place were you should not try to save money.