Almost every NFL team has RPO in their playbook. It's a constraint play that forces the defense to defend the width of the field, tighten their alignments in the secondary, and it gives the defense 2nd thoughts about blitzing or aggressively defending the run. It's not a foundation of an offense and it doesn't prohibit an offense from any formations, calls, philosophies, etc. You can do RPO out of shotgun spread or under center with 3 TEs and 2 backs. I don't know why the fanbase is so obsessed with it.
The most important traits for a QB to execute RPO are a quick set-up (footwork) and delivery (ball placement). Kaaya is better at those traits than Perry is regardless of whether Perry runs a full second faster 40 or not. Mobility and athleticism is barely relevant to running RPO, but footwork is and Perry's footwork is unrefined. RPO is not a factor in who starts for Miami in 2017.
If that's the case, I like Sherrifs' chances, because the coaches have said he has the best footwork of all the quarterbacks (including Kaaya but not Perry and Weldon).