Focus Point should work for all different kind of Elements
Hero Slider
All Banners/Sliders
Media Asset itself when included in a Page
Hero Slider
Here you should see a difference in the Image, on which part the Focus Point falls.
Banner
Here you should see a difference in the Image, on which part the Focus Point falls.
Slider
Media Asset
Here the Focus point would not make any difference, because you always see the whole Picture itself.