What is design considerations of policy-based routing?

PBR is a forwarding policy mechanism and plays no role in failure detection - it does not interact with BFD, hello timers, or any other detection protocol to decrease detection time.

PBR applies forwarding decisions based on match criteria such as source IP or TCP/UDP port using route maps, bypassing the normal routing table. During reconvergence, routing table updates propagate at different times across routers while PBR policies remain static, causing inconsistent per-hop forwarding decisions across adjacent devices that result in microloops.

Routing traffic through different exit points based on user groups describes the intended purpose and operational capability of PBR, not a design risk or consideration.

PBR uses route maps and extended ACLs to match and redirect traffic - it does not use RSVP, which is a signaling protocol for traffic engineering and bandwidth reservation.