Ok, there is a way I can see, but it will be painful.
I had have a machine and it was running.... Stretch and an early version of NR.
I wanted to install a new bit of code, but time bit me in the bottom and I couldn't.
So I rebuilt the machine, ground up.
and now I have NR 4.0.9 and Dashboard 2.x installed.
That ain't gonna work with the old flow/s and the OLD dashboard nodes.
Options?
Ok, I could install the older dashboard, import the flows then migrate the nodes to the newer ones.
I don't believe so. Install D1 since it runs in parallel anyway. Then take your time to migrate to something newer - maybe even avoid future similar issues by migrating to UIBUILDER
Either way, you can take your time. I doubt D1 will disappear any time soon.
Honestly, I prefer to reinstall from scratch when I can. It tends to end up with a much cleaner installation and fewer issues. I see this as an advantage of using small, cheap(ish) devices, harder to do on a full server unless you have a spare.
I feel your pain moving to DB2. It took me months to get everything over and much gnashing of teeth but you really haven't got any alternative as sooner or later you will have to do it. One more update due to deprecating code. My thoughts are to do it sooner than later and fortunately there are several here who are willing to help if you get stuck in a corner.
You DO have an alternative. It does get rather frustrating to have to keep saying it.
One of the whole design criteria behind UIBUILDER is to be able to avoid lock-in to front-end frameworks.
D1 and D2 are great for getting going quickly but, as with any framework, they lock you in to the specific framework (and possibly to a specific framework version).
With UIBUILDER, you are using enhancements to vanilla HTML/CSS and not using a framework. Or, if you prefer, you can lock yourself into ANY framework.