But the reality is from the description of this, the manufacturer has done a crap job of building the "networking" part of this, and if you start trying to be clever and hook it up to an actual network you might really fsck it up.
So, imagine some field tech decided he'd rather find a clever new way to fix things, and then hoses (pun intended) the pumps because he's doing something which the pumps can't actually be made to work with.
Who the hell do you think is going to fix it?
You can call it a networking problem, but I would suggest if the manufacturer has given them all the same IP address ... these things aren't designed to be "networked" in any meaningful sense of the word.
Do you really want to run the risk of fucking up the pumps because you think you have a solution which works?
Because setting up a bunch of VMs so you can hook them up in a clever way and try to do this in parallel sounds like you have a better chance of it going wrong than going right.
It may use some networking technology in a limited way, but it isn't a networked device ... from the sounds of it they use that networking port as little more than a serial connection. And if you start trying to connect them all at once with some fancy setup of your own, you have no frickin' idea how it's going to work or what will happen.
You don't want to explain to the gas station owner why he has no working pumps and why the company who makes them wants no part of what you broke by doing it in an unapproved way.