Would like to consider using page builder alongside other drag and drop page builders, e.g. Elegant Builder.
As a low-bar, perhaps you could do as they've done and have a per post/page toggle to turn page-builder on/off.
High bar would be if both might be used together.
e.g. use page builder to provide the post-loop; use elegant builder for widget layouts they do well as well.
Seems like the on/off tick box – could – be a quick/easy win.
The high bar request seems possibly significantly more challenging.