Out of State Supervised Visits

My question involves a child custody case from the State of: Missouri

I am in the process of taking my ex husband back to court to modify our custody agreement. The circumstances leading to this are long, but I'm requesting supervised visits for his contact with the children. The only difficulty is he lives in Missouri and I live in California. When talking to my attorney she had not had a case like this before so she wasn't completely sure how it would look.

Does anyone have any experience with out of state supervised visits? I am fine having myself, my parents, his mom or sister present for the visits with him and the kids, so it doesn't necessarily have to go through the state supervised visits center. I am the one who makes the trip multiple times per year (usually 4/5 times including 4-6 weeks during the summer). In almost 4 years of living out of state he has never visited the kids here. I'm just trying to get an idea of what the options might be since the normal weekly supervised visits aren't really an option.

Out of State Supervised Visits