Q is the pedal to pedal width.. right hand angle cranks win on that ,
the 65-P-110 spindle in a track bike with a 65mm width BB shell , and 110 wide rear fork,and hub.
would be about as narrow a Q Crank As I can imagine..
to use 2 chainrings and 5 cogs in the back the Right end crank has to move outward ..
Modern cranksets no longer have straight crankarms, so the Q cannot be as narrow, but the way
the crankarm is designed has let the BB spindles be shortened. and the bend arms shapes
are less likely to hit your ankle bone on the end of the Arm..