Well, I see your point.
Previous threads, some drillers advised to go 1/8 forward for your fingers, if you will use 1/8 lift grip to cancel the pitch to the degree you should have. However, some others advised not to do so. Because the pitch of the finger grip is only on the front part of it. Therefore extra pitch will effect the inside of your fingers but will not effect your nails (means do not create any problem for your nails etc.).. But when you change the pitch of the hole, you change everything.
Although there are methods, scales etc to determine the proper pitch, it is the matter of good grip and feeling in the end. Best way is to experiment.
The problem you have mentioned "finger nails sliding tight" can be caused by other reasons. Grip can be too tight for instance..
By the way, sometimes it can be confusing so please note that when I say "forward pitch for the fingers", I mean "away from the palm". And I mean "to the palm" when I say "reverse".
Regards,
Burak