I prefer
Lucille.
Lucilla seems frillier to me. I like
Lucia or
Lucinda better, too. That's how I feel about
Philip /
Phil. I think if I were to use it, I would just always call him by his full name and politely correct others if they don't do the same. If he were to choose
Phil, that would be different, though. Not sure what else one could do about that except not use the name at all, and that's so disappointing.