SFO Global entry
 

For those of you who went through the security at SFO, is there a Global entry(Nexus) only line? I am thinking to maybe step out for a quick smoke... while waiting for my next flight. My first leg is YEG-SFO arriving local time at 9:50am, and next flight departs at 1:10pm; SFO-ICN. So I have about 2.5 hour window. If there is separate Nexus lane which I can take, then risk of missing or even running to catch my flight will decrease. If there isn't one, I guess it is time for me to quit...

(1) It is time for you to quit, and
(2) TSA Pre-check (via GE) is airline specific and unless you're on UA, I don't think you'll have Precheck on the connecting segment, which is what you need for the quick security.

I believe that right now the only non-USA-based carrier that participates in pre-check is Air Canada. So as Eastbay1K pointed out above, your only hope is if you are on UA for SFO-ICN.

(1) There is no express lane for GE at security checkpoints in the USA. GE only applies to CBP entry checkpoints when you are entering the country.

(2) If you have GE you can sign up for pre-check by entering your GE # in your airlines' FF database. That will usually (but not always) generate pre-check on your boarding pass.

(3) SFO has pre-check at all domestic and now at the international terminal, I think. The lines vary depending on the time of day but generally faster than the normal lines.

(4) SFO also has CLEAR which is guaranteed to expedite your security checkpoint experience. But you would have to pay a fee and get pre-cleared by CLEAR, which might not be possible in Canada.

(5) Your math is bad - you have 3+ hours between flights. That is more than enough time to navigate CBP and TSA checkpoints, and to smoke a whole pack if you puff quickly :)