Okay, you’re not really using Node-Red to the best of its abilities then.
The best way to structure your system is to only run MQTT code on your devices, so that they communicate directly with Node-Red, not with Blynk.
Then, you use the Blynk contrib for Node-Red to send data to Blynk. You’d also save that data in a database to display it in the Node-Red dashboard.
I explain this approach in more detail here…
The data extract process from Blynk via the API is explained here…
and this API can only be called a maximum of10 times in any 24 hour period.
I don’t see how you’d be able to use this to obtain meaningful information to use in Node-Red.
You said that you’re using…
Do you mean the SuperChart widget that allows upto 4 datastreams to be displayed with your subscription?
Pete