CSS style scoped - do I need to add support to includeHTML?

Question

css

Hello.
Continuing the development of the inlcudeHTML JS library (an analogue of the include() function in php for the front-end), I asked myself the question:
Do I need cross-browser support for isolated CSS styles for the selected block through processing with a JS script?
Now, the situation is this: caniuse.com/#feat=style-scoped
Ie, does anyone need it or "score" on it?
In advance, Thank you all for your replies.