SKETCH : How to updade a Button's Symbols but not change the TextLabel's content?
So that the text can be updated freely without duplicating itself to all button instances?
In other words, the button symbol just retains the styles and not the content.
The closest thing i found was this plugin/technique.. but it seems out-dated : http://brilliantsketch.com/sketch-symbol-plugin-bring-smart-object-sketch/
Symbols - Exclude Text (from Sketch documentation)
You can easily do this with Symbols, by selecting a text layer inside a Symbol and checking the Exclude Text Value from Symbol checkbox. Any edits you make to the text are now local to only that instance.