He knows about this weakness of Add's, which is why he enjoys asking about them. It's fun to listen and it holds his interest, unlike other people's words, especially when they try to get something out of him. How unfortunate.

"That sounds useful." Especially if efficiency can be preserved. There's a lot of applications for these sorts of things. "So how does it work?"

Nobody is close enough to them to eavesdrop, he thinks. He made sure to 'suggest' to the closest bar attendants that they forget about him and Add.