That will be what’s eating your rears..
LR pads are metal, so eat the rotors just as quickly, and their rotors aren’t the hardest material.
Add to that the dust churned from the front, it goes straight into the rear pads accelerating their wear.
Also sounds like your TSA is really working at times to generate such dust levels.
I’d suggest looking for a T2 or T3 slotted rotor and some ceramic based pads.

