Everything I have read indicates you have nothing to worry about until such time he can meet the very high standards of convincing a court that he has fulfilled and can met his obligations both to the court and his kids.
Guardianship Vs Adoption - Family | Laws.com
In short, he needs more than just a lawyer to overcome his sad history of poor actions and choices. Does he OR mom have a regular schedule of visitation
court approved or OTHERWISE? I ask because this is usually the first area of concern for a judge/court, even if financial obligations are met.
Occasional diapers being bought means NOTHING.
R***E***L***A***X.
It's not a simple easy thing to regain custody/rights after a court has appointed a permanent guardianship.