"I was really looking forward to having Docker available. I run 5 or 6 jails at home and they have been the absolute biggest pain point for me." Can you elabor

"I was really looking forward to having Docker available. I run 5 or 6 jails at home and they have been the absolute biggest pain point for me." Can you elaborate a bit ? I have done a bit of work with FreeBSD jails and have some sense of their pros and cons ... were you using pre-built jail userlands that you got from some third party (ie., you did not build or replicate yourself) ? Genuinely curious ...