I picked up one of these adapters.
Partially, like a few others in this thread have said, as insurance (a just-in-case scenario).
But the main reason is that my daughter won a raffle at Hot Bins for a Lectron L1/L2 tesla EVSE.
I keep the Tesla EVSE with adapter in my Leaf, the original Nissan L1 EVSE inside the front door at home, and I have a Juicebox Pro 40 mounted in the garage.
Keeps me covered and then if I'm out and about I can lend a hand to any other EV owner in need, regardless of EVSE type.
Edit: Fixed incorrect "charger" terms.