If your neck whiskers grow medial-lateral (or the reverse), then a 2-3/4 inch straight will simply not perform an ATG stroke across all the compound curves that present themselves (without threatening massive blood loss).

In such a situation, the N-S and S-N passes will be XTG. To get a little closer, I also do a NE-SW and NW-SE pass, accompanied by scything, which is as close as I can get to a true ATG pass.

This gets me close to BBS on my neck. I can still feel remnants if I stretch and rub ATG on my lower neck, but they are unnoticeable visually, and are under the collar of my dress shirt, anyway. I used to finish them off with an SE, but don't anymore, except occasionally for my own amusement. I'm still better shaved than 99+% of the other testosterone-carriers out there, and I achieved that with a 150 year-old implement that I honed myself, so I'm satisfied.