I'm in TAC. I see a Closed enhancement request bug (internal one) that requested global statistics and per-interface statistics for RPF.
According to the bug, there is no plan to implement global statistics at this moment.
Could you please talk to your Cisco representative for further disscusstoin of this request ?
I really appreciate for your suggestion that makes our products better.
I will send you private message the internal bug id that makes easier when you talk to your Cisco representative.