This is why I've been holding off on trying to develop cross-platform software that talks to microcontrollers and then executes code- because I want the UI / GU

This is why I've been holding off on trying to develop cross-platform software that talks to microcontrollers and then executes code- because I want the UI / GUI experience to be fluid, and for things like selecting something you want to change to highlight that element on the board itself- there's no well-defined method for doing this, nor even a once-trod path, and definitely not anything for those who don't know where to look. Does anyone have suggestions for cross-platform UI's? (Not Electron)