I am also playing around with pyfreebilling. It's all on LXC containers. I have one concern, Freeswitch won't startup in an unprivileged container so I am using regular containers on Proxmox. After going through the pyfreebilling forum and implementing all the fixes you suggested (still not in the install docs) it seems to be ok. However, I do have concerns regarding the fixes and updates with pyfreebilling so I plan on sticking to LCX for now until these issues are addressed. Will start a new thread regarding pyfreebilling issues.