Most of your variation in length comes at the nose, especially with coated bullets.
If you are using a seating die with an anvil that seats off the ogive, that variation in bullet length isn't going to mean anything ballistically. Your OALs won't be super consistent, but your seating depth will be, and your standard deviations in velocity should be consistent as well, all else being equal.
On the other hand, if you're using an anvil that seats off the nose/meplat, it will result in consistent OALs, but inconsistent seating depths, which is going to increase your standard deviations on muzzle velocity. Will those differences in velocity result in significant differences in performance at the shorter ranges common to pistol shooting? Probably not. But if you're looking to produce the most consistent ammo possible in terms of performance, or if you're chasing the power factor floor, you'd be better off seating off the ogive with such bullets (with any bullets, really).
