I am using recommended wave washer plus 2 1mm spacers on non drive side. On the drive side I removed tensioner and spacers and used the 13mm sleeve spacer. When measuring from the single boss at the bottom of the triangle above the crank… center is 2 3/8 inch from center of boss to inside of each crank arm. SRAM says do not use any spacers on driver side in addition to the 13mm Spacer sleeve.
This spacer configuration offsets the Crank to the non drive side by 3/16 
Any suggestions on if the boss is a good centerline to use as a reference point? Or do you shim up the drive side to bush crank toward the right ?
You want the chainring to be in the right location relative to the cassette. ‘Centred’ to the BB is irrelevant, so use the spacer setup as instructed to get you the right chainline alignment.
You want the chainring to be in the right location relative to the cassette. ‘Centred’ to the BB is irrelevant, so use the spacer setup as instructed to get you the right chainline alignment.
Or am i missing something here?
Given that the saddle at the centerline of the bike, you might want to have it centered between the pedals…