I'd want more than 2 threads overhanging the edge of the dropout, myself, but do as you wish.
The cap on QR skewers is Cupped, and the Tapered Coil spring should all collapse into that space ,
So axle just short of flush with the outer face of the dropouts, is my pick.
Last edited by fietsbob; 09-05-13 at 02:04 PM.