[A930Rocket]

I’d probably go with the longer lag screw in galvanized or stainless steel in a mortar joint. If it’s a little long, it goes into a stud or air pocket. Maybe even OSB if your house is sheathed with it.

I think once you start drilling, you will find that there is mortar inside the openings and the backside has a lot of mortar as well, especially at the joints.
FYI, I never use those plastic inserts. They always seem to fail.