This is not a trivial attack. Within the short key negotiation phase, the attacker must simultaneously prevent the two devices from hearing each other, and be transmitting in their place at the exact frequency hop and interval.
"The attacking device would need to intercept, manipulate, and retransmit key length negotiation messages between the two devices while also blocking transmissions from both, all within a narrow time window. "
"The attacking device would need to intercept, manipulate, and retransmit key length negotiation messages between the two devices while also blocking transmissions from both, all within a narrow time window. "