I'm fannying around with SLX cranks on the SS. I can play around with the B.B. spacers to try and make the cranks have an equal gap either side between the crank pedal end and the chainstay clearance. This is correct yes?
Which means Wong
Do you need equal clearance?
Get the chainline bob on and use the spacers to do that as a priority me thinks... especially on a SS
Dunno, that's kinda the Q
The chainstays are rarely symetrical, that'd be a good reason not to use them as a basis for crank spaceing!
Stick the crank in whatever the default position is, and tune the chainline with spacers on the casette (or chainring position).
I'd try and keep the cranks equidistant from the centre of the bike and play around with spacing on the back if you're using a freehub, sprocket and spacers. If you have a SS specific rear wheel then you've got no choice but to adjust at the front, I guess.