You guys need to stop going to shitty shops and expecting perfect work. The "pedestrian" shops will look up the alignment specs, and alignment tolerances, that Mazda allows for the car, and if it falls within the specs, they will stop working on the car and send you on your way. A difference of 0.4deg camber left/right is not necessarily outside of the tolerances allowed by Mazda.
Find a reputable race shop if you want a good alignment, and tell them exactly the camber, caster and toe you're looking for. A good tech should be able to max out the machine's sensitivity. On most Hunter machines that means camber and caster are +/- 0.1 deg, and toe is +/- 0.01deg. If you ask for that tolerance you can weed out the shitty shops -- "we're just going to go to the specs" -- vs. the real, serious outfits -- "who do you think we are? Of course we can do +/- 0.01!" -- very easily.
For people who don't know what settings to choose, do this. A general rule-of-thumb for a daily driven street car.
Start with the following settings:
Front Camber 0.5deg
Rear Camber 0deg
Front Caster MAX (as much as you can manage; make it symmetrical)
Front Toe 0deg
Rear Toe 0deg
Add 1deg of camber, front and rear, for every time in a week that you corner really hard for a continuous stretch of time. So if you just putt around normally, stick with 0.5deg/0deg camber. If once in a while you'll go for an AutoX or canyon run then you can get away with 1.5deg/1deg. If you're attacking the turns all the time, then you should allow yourself 2.5deg/2deg to keep the tire wear even.
Having just destroyed my tires in the last 3000 miles, I no longer think it's a good idea to run any significant semblance of toe, in or out, on the car. Unless you're seriously racing the thing, just stick to 0.00deg toe all around.