Would I have an issue including papers with the divorce papers for him to sign over his rights?

We were married June 2007. We had one child together in 2009 in which he left us both a month after she was born. He lives in another state. Almost ten years after marrying him and eight years after he left, I have found an affordable divorce attorney. I have since been in a relationship for almost five years. My current fiancé has been a father figure for my daughter since she was three. We plan to remarry and him adopt our daughter. My ex is willing to sign over his rights. He hasn't been in her life but maybe nine months all together on and off but not in almost two years. She will be eight soon. There is a current child support order (he rarely pays), that would obviously be canceled once he does sign.