Ok,thanks so I´ll play play with the nextion , but i think that will end up in a rewrite of the UI.
May be that would be a solution for a config without controller , just sending commands over Serial.
So i will be complete user defined, nothing for general implementation.
Think I´ll let you know when i get a running system, as you know my main intents are from CNC side ;-)
BTW, got my heaters / Fans controlled over the I2C now , works nice