With the neck placed in the pocket, I can use a straightedge to determine where the strings will fall, so I can see what the alignment of neck, string and bridge will be, and make any subtle adjustment necessary to have everything visually correct, which is far more important than things being technically correct, with the exception of that first string bridge… that’s gotta be right.
Just to be sure it’s all square relative to the presumed centerline
Now mark the location of the bridge’s mounting screws..
rk