So could work for the low risk café stop situation, but no real advantage over an alarm padlock. The back wheel on my ebike is a PITA to remove, so the thought was if an alarm lock was on the disc it would put off the opportunist thief. Just a thought.
I may work in that incidence and one advantage of most Ebikes is that they're very heavy to carry.
I still wouldn't trust it on its own tho, i always lock my bikes to something, even if they're only left for a few minutes.