Like I said, I'm a major creature of habit, so I completely understand the whole "change is bad" thing..
When it was being discussed that the docker plugin was going away in favor of Portainer/Cockpit for OMV 5... I actually installed Portainer (alongside the docker plugin) on OMV 4 and used it to get comfortable with it's use. Only took a few hours and I found it just as easy as the docker plugin and probably within a couple days, I just went ahead and uninstalled the docker plugin on OMV 4 and am now just using Portainer on OMV 4 for container management