Still dont agree but if it works for Ryan good for them or yo guys.
In my company they trial the use FO as SFI for less than one year to train other FO (If I remember the trial last 7 to 8 months). Same as ryan, procedures, etc on the first 4 or 5 days of a type rating, then a training Captain overtakes the training. They even give recurrent training to other FO. They were never allowed to give simulator to a CAPT or a FO upgrading.
But after the trial, the general concern is that a Captain can transmit a lot about the job more to FO than other FO. There quality of training wasn't as high as the company wanted so they drop the idea.