Most non-precheck lines actually have the paper/plastic sheets that they hand you so you don't have to take off your shoes (you still need to take your laptop etc. out of your bag).
They're meant to be used when the precheck line is closed, but if you do end up there, it's worth asking and saving you the 2' and the "please stand on the yellow marks where 10,000 other pax just stood, with or without socks". Worst thing they may say they don't have the sheets or refuse to hand you one.