XH is an emotional mess. A man who left his wife and daughter. Appealing to his morals, loyalty, heartstrings, and such is likely to push him further away. Which is the opposite of what you need to get this business matter resolve.
Yes, what you said is true. Girls with a healthy relationship with their Dad will be more self confident and have higher self esteem. The relationship XH current puts forth is not that. And he knows it. Your message will be a huge pile of pressure to him, and that scared little squirrel will bolt.
Stick to the business details. Sans emotional tugging (mostly). MLCer’s emotions are already cranked to eleven; they cannot handle any more or any one else’s.
D
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.