Eh, if I really loved a name I'd just dedicate myself to correcting people who tried to shorten it. Being a
Madyson you'd think (especially with my spelling) that people would call me Mady but I have NEVER answered to that name (save a few close relatives who called me Mady occasionally while growing up).
You have to keep in mind also though, that your child might CHOOSE to go my the NN you hate. Even with enough diligence to get everyone to NOT call
Penelope Penny. She may want to go by
Penny, at some point.
randome note: I really like
Abigail but hate
Abby AND
Gail - actually I've always loved the idea of calling an
Abigail "Bug" :)