So for the pages where you’re using sections you need to set the Page Builder container to Full Width.
Within the Sections themselves you have the inner section width which you should set to contained, this by default will respect the customizer container width.
To change this for a specific section you will need to use CSS:
1. Edit the Section on the Settings tab give it a CSS class e.g section-width-800
2. Add this CSS:
.section-width-800 .grid-container {
max-width: 800px;
}
Then you just need to add the section-width-800
to any section you want to reduce its content width on.