Example,
I really just keep pulling them in and out, erratically bending the wires, until they are reasonably flat.
Particularly with modern flat rockers/plates (radiant etc) I notice they really don't look good unless very flat, zero yaw. (And indeed you gotta get the depth just right.)
Do pros have any tricks to make it easier ?
Another example, on this 3gang, notice the #3 is definitely still yaw'd a bit CCW on z. I just couldn't get it better than that.
(Note, the #1 is well proud, unfortunately the wall box was a bit damaged and the only fix for that would be some more serious effort ☹️ or a really long rough wood screw 😅 )
Also looking at it, the #2 its a tiny bit yaw'd CW on z, not perfect 😕