Ah yeah, that case.
$content = apply_filters(‘the_content’,$content);
simply should do it, applied by whatever that page builder uses to pull the content. It should be pretty simple.
If you would consider any alternative, many WP themes’ visuals can pretty neatly be recreated by using other themes. After all, most are a major landing page, then the inner pages are pretty much the same template.
Generatepress is one of the consistently praised ones for everything, especially noted for its speed, which is a major factor in search ranking and user friendliness. It has a never seen before 638 5 star ratings, and a very happy user crowd.
The free version works great by itself, however premium version pretty much enables many site formats by just importing them.
What’s most important that the theme sticks to WP specs and methods pretty tightly. Another point of admiration by its crowd is how it integrates WP’s customizer that makes so easy to modify the theme from WP admin to maximum extent.
If you combine this with a page builder like visual composer (now visual bakery i think) you could reproduce any theme visuals you prefer.