I have a solution for me and don’t need another one, everyone interested in that can use my code I presented here, that was the only purpose of my post. 
But to answer, of course - who does not know node-red. 
I use node-red for some automation tasks locally on the Cerbo. I also mentioned that in my post.
Not to mention to use MQTT or other protocols and many tools that go with it (Grafana, …). All this is nice especially if one does not want to dive into C/C++ programmming, no question. But it always requires a client running a web browser, which is a significant overhead. If I really have the need to change something in the system, I can just use my (actual) phone or notebook and the VRM portal. But this is not the main topic of my post. It is not a relevant use case for me, as it rarely/never happens anymore. I just want to display some data for monitoring purposes to “sychronise” some energy-consuming work at home a bit better with the sun, so to say.
So, I might spend a lot of time to get my old Nexus I have working as a monitor display - what for? To wait that it will finally die - or even worse it’s battery explode, as I can’t simply remove it. I have to connect it all the time to a power supply, otherwise I wait for ages to get it booted. 
I also won’t buy now old phones just for the use of some data displays in my home. I already spent too much time for that experients, way more than finally organise the display and writing the few lines of code for it…
Those CYDs are cheap, brand new, do not require batteries or other overhead, are low power, boot in seconds and if one should really die, I have the same one one ordered and (re-)programmed again w/o any fuss in minutes. Just need to wait a few days for the delivery.