The friends vs civil co-parents is a huge hurdle for me too. I feel like his BFF, ex wife, wife, and person he hates most all depending on his mood for the day. If you find out how to be a civil co-parent without coming off as a good close friend let me know because mama is struggling here too. We talk everyday so it makes it hard for me.
The solution based therapy might be good for both of us. We really should look into it.