As Agave said, you don’t have to boresight them. I find the annoyance of the boresight procedure generally not worth the added benefit of the TGP in a lot of cases. I use the missiles more in VIS and PRE mode these days than anything else.
That said, 65’s are fickle monsters and even when you’re very comfortable with the procedure you’re going to miss sometimes because something wasn’t just right. Generally it’s best to have a mental checklist you run through real fast before firing. Steady cuing cross -> Keyhole -> Solid lock cross -> All yes? Rifle.