Desktop vs Mobile Background Image Options?

I am wondering if this is possible right now. The goal is to decrease Largest Contentful Paint (LCP) in HERO sections, in particular, the background image loading in mobile.

1. Using GB Container, can the background image differ between desktop and mobile? ie. different image files

2. Using GB Container, can the background image differ in thumbnail resolution between desktop and mobile? ie. instead of choosing large, can we choose medium let's say.

3. Can GB Pro allow for a pot template to be created to control how all Posts will display?

4. If #3 is Yes, then is there a way to choose appropriate desktop vs mobile images within background of containers using GB blocks when displaying a top HERO section?

The goal is to try and decrease Largest Contentful Paint which is almost always the HERO image on mobile. Without the ability to control the above, LCP is sure to fail all mobile devices.

I have tested various options and I think there are 2 methods of improving LCP. One is to choose another image all together for mobile and the second option is to be able to choose a lower resolution of the same image (medium instead of large).

Any advice would be awesome.

Thanks!