Which limitation of CoreXL is overcome by using (mitigated by) Multi-Queue?

This is not a CoreXL limitation; CoreXL does use traffic queues as part of its packet distribution mechanism.

This inverts the architecture - in standard CoreXL without Multi-Queue, one queue is shared across CPUs, not several NICs sharing one queue.

Multi-Queue resolves the CoreXL bottleneck where each physical NIC was restricted to one receive queue tied to a single CPU core. By enabling several traffic queues per NIC - each processed by a separate CPU core - Multi-Queue achieves true parallel packet processing at the interface level, significantly improving throughput on multi-core gateways.

This describes the CoreXL limitation that Multi-Queue solves, not the outcome that Multi-Queue provides; it is the problem, not the answer to what is overcome.