LT and LS rotors are the same size.
It's the SS rotors non Brembo that are larger.
Your right about the undersized that why I posted Solman98's thread, in post number 4

 

But you said the rear brakes are "fine". Rear brakes not doing their job is the ONLY reason for all 4 of the pads to wear out prematurely.


BTW, the break in procedure is NOT a full stop from speed; if you come to a full stop with hot brakes deposits will occur.
Proper way is to ALMOST stop, come to complete stop after cool down.

Look at your rotors after a panic stop; you will surely see the outline of your pads.

I am of the no resurface school. The only time I do anything is when I want to save a couple of dollars and have a coupon for rotor turning at PepBoys. But I never let the rotors get too groovey.