Your issue is not the alignment but what's causing it to be off!
When the car is aligned it is stationary using figures for a new or slightly worn suspension. When you are driving, he suspension is under more load and is moving and changing. If you hit a bump, camber changes (in the negative direction) and a worn shock or spring/strut will allow the car to oscillate up (positive camber) and down (negative camber)for a longer period meaning the tire is in more negative camber situations causing more wear. Lets not even throw toe into the mix which changes also causing more inner tire wear! Toe changes also occurs during the oscillations adding to the wear.
Your shocks/struts and springs may be worn causing issues. I had extreme feathering on the rear of my MDX with the electronic shocks. Acura replaced the first set around 80K under warranty when that was occurring and I paid for new tires. Had the same happen again around 140K on the MDX again with the electronic shocks. New tech model assemblies on the front and new springs in the rear with new struts and it's better than ever in a sense. A bit softer than the sport mode that I'm used to but rides well and no more bad wear.
Get new shocks/struts and springs along with new sway bar endlinks and you will notice a significant improvement not only in ride quality but tire wear.
It's about 2 hours for the rear for labor and 2.5 in the front plus alignment for the new parts. I'd also recommend having a mechanic inspect your inner tire rod ends as well, common issue for MDX's where they wear at higher miles esp with worn suspension. That's an additional 1.5 hr labor to do. The steering will feel much more direct and less sloppy with them replaced if they are worn. Same with outer tie rod ends if they are worn.
Rock auto has been great on pricing plus shipping vs other places including amazon with the 5% off coupon code. Beck Arnley parts are usually parts are pretty good and I used those on the MDX for my endlinks and tie rod ends and am satisifed vs Moog!
2013 TL Advance 3.5L
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2010 Honda Accord EX
2006 BMW 760Li
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2007 MDX Sport/Ent.
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