It’s likely that very small non-centeredness makes no difference to the beam center intensity. Even with a small LED like the WF there is some room for error.
You can check whether the focus is good enough. If you make a pinhole in a piece of thin cardboard or Al foil and move it around the reflector face you can isolate the parts of the beam from different parts of the reflector. Essentially if the isolated beams from different parts of the reflector overlap at the beam center than you are utilizing the whole reflector area and the beam intensity is maximized. My description is probably not clear to someone not already familiar with these ideas, but see here for a more complete procedure.
On second thought, this test is sensitive to the vertical focus of the LED, but I’m not sure if it works as well for lateral focus.