John, were you able to preserve your dockers or anything else when you started over? I'm considering doing the same thing and just saying the heck with trying to upgrade in place. It sounds a bit problematic. Hopefully future OMV versions won't be so different that an upgrade in place works, but it sure looks like too many changes under the hood from 4 to 5 to make this one as joyful a task.
That said, I love how this software continues to grow and get better all the time! You guys rock.