Virtual Switching Extension (VSX) is a high-availability technology that allows two ArubaOS-CX switches to operate as a single logical device. Split-recovery mode is a feature that prevents traffic loss when the Inter-Switch Link (ISL) goes out-of-sync and keepalive subsequently fails.
When split-recovery mode is enabled, the secondary VSX member disables its downstream links until it synchronizes with the primary member. When split-recovery mode is disabled, the secondary VSX member keeps its downstream links up even when it is out-of-sync with the primary member. Disabling split-recovery mode does not affect how the primary switch takes over again as the primary switch after a failure and reboot. The primary switch always takes over as the primary switch when it comes back online, regardless of the split-recovery mode setting.
Therefore, this is not a use case for disabling split-recovery mode on ArubaOS-CX switches in a VSX fabric.

Headend replication is a method of handling BUM traffic in VXLAN networks without EVPN, where the ingress VTEP replicates every BUM packet and sends them as a separate unicast to the remote egress VTEPs in the same VNI1. This avoids the need for multicast routing in the underlay network, but it can increase the load on the ingress VTEP. Therefore, this correctly describes how the VTEPs handle VXLAN traffic forwarding without EVPN.

Virtual Extensible LAN (VXLAN) enables multiple isolated Layer 3 domains, each with its own routing table, to share a physical network is not a way that a data center technology can help meet requirements for multi-tenancy. Multi-tenancy is the ability to provide logical separation and isolation of network resources for different tenants or customers on a shared physical infrastructure. VXLAN is a feature that provides Layer 2 extension over Layer 3 networks using UDP encapsulation. VXLAN does not enable multiple isolated Layer 3 domains, but rather multiple isolated Layer 2 domains, each with its own VNI.