What are two possible drawbacks of ending Loop-Free Alternate to support fast convergence for most destination IGP prefixes? (Choose two)

LFA coverage is highly topology-dependent - not all IGP prefixes will have a qualifying loop-free alternate neighbor, so the network topology may require redesign (adding links or adjusting metrics) to achieve alternate-path coverage for most destinations.

Sub-100ms convergence is a primary goal and achieved benefit of LFA, not a drawback - LFA is specifically designed to enable IP fast reroute in under 50ms upon failure detection.

LFA supports both internal (intra-area, inter-area) and external IGP prefixes, not exclusively external ones - this statement is factually incorrect regarding LFA's scope.

LFA can be deployed within VRF OSPF instances; there is no architectural restriction preventing LFA from operating in VPN VRF routing contexts.

Computing LFAs requires additional SPF runs beyond the primary path calculation - specifically, the router must execute SPF from each neighbor's perspective to determine which neighbors qualify as loop-free alternates, increasing CPU and memory consumption.