I noticed in the project that you have master component in the first artboard and then you have component instance on the second artboard. I would put the master component on the pasteboard and then duplicate instances in the artboards.
The master component has a solid green filled diamond in the upper left corner and duplicates have a solid white fill.
If a component instance is modified it has a filled ellipse in the center of the diamond.
I would give the master component a specific name. This name will propagate to any component instances and then that component name will be added as the first class in the code.
For reducing code have any instance (duplicate) remove all styles and add back in the ones you need. For example, I added two components to the same artboard. In the second instance I removed all styles and then added back in the top, left and position styles.
The class is reduced down to:
First component instance on the artboard (for comparison):
You can then rely on the component name being in every duplicate instance and that class and properties to it’s own style declaration. Theoretically the software could figure this out but that would be a feature request.