If there is a move to drop the Docker plugin for Portainer, why not use Cockpit, it's easier to use and understand and not as daunting as Portainer. I've tagged the OMV version as 5 purely for this thread.

I was looking more at the KIS principle, I have been poking around portainer and trying out jellyfin, it did throw something odd that I wasn't expecting nor understood.

But I thought about Cockpit in regards to VM installs as well instead of VB, but there is one caveat to that

I would agree but a new user could look at portainer and it appear rather daunting compared to the current plugin, but with Cockpit you get 2 for 1

There is one which I need to try out with Cockpit, selecting the networking, host, bridge etc. Also one is unable to create a Vlan from within Cockpit for VM's.

So you've got a new comforter

There appears to be one caveat with Cockpit, it requires Network Manager! if you look at TDL's video Cockpit's Network Manager is not installed.
This creates 2 problems; 1) There appears to be no way to select a network setting in docker. 2) You cannot create a VLan in the VM section, having experience of MS Hyper-V you create a VLan for each VM.
What I believe Cockpit is doing for VM without Network Manager is to use NAT, which if memory serves me correctly is the default for VB.

I am going to test a theory with Cockpit, I have installed Cockpit's Network Manager this appears in the menu on the left, but whilst it locates my NIC it knows it is not associated to NM.
My current OMV4 runs off a USB Flash Drive, I have 3 in total, 1 x Master and 2 I rotate on a monthly basis, I have created an image from the current working USB I intend to write that to other 2 USB's and test them to ensure they boot. Once that's done I'll use one to boot and install Network Manager on OMV, this is against the norm as OMV uses ifupdown for networking, but it's the only way I can see to allow Cockpit to access the NIC. However, this has to be changed in the NM conf file

[ifupdown]
managed=true

the above change allows NM access/control over the current ifupdown configuration.

Is this a good idea, don't know, that's why I shall test it knowing I have 2 working USB's to fall back on.

I have not ventured into uses OMV5 I'll wait until it comes out officially, my thought was it that Cockpit IMO is more user friendly than Portainer. Again IMO with Portainer it's an advanced front end for Docker, and for some could a steep learning curve after the plugin, hence why I started the thread.

Probably in the Cockpit community, as of 1.99 you can now select a shared folder for deployment of VM's previously as with 1.88 the VM would be stored on your boot drive, not a good idea.
TBH what you have suggested makes sense considering there is a cockpit-storage plugin, but you could use FTP to copy and paste a complete path rather than type it all in.

That's the reason I want to test this on working OMV albeit OMV4 because I think that is the reason that cockpit docker has no host or bridge option like the plugin, it could be you have to set that up in cockpits networking e.g. create a bridge, whereas the default for cockpit docker is host, + where some dockers such as Pi-Hole require a MacVlan, in this case you would use a Vlan created in cockpits networking.

I suppose so yes, with hyper-v the networking is set as a vlan, I know when I last used vb I had to change the networking, this allowed the vm to be exposed to the local lan and the internet which at the time was necessary for my W7 install.